public inbox for [email protected]
help / color / mirror / Atom feed[PATCH 06/12] fixups.patch
46+ messages / 2 participants
[nested] [flat]
* [PATCH 06/12] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 3374012940..807597e648 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index ac3884b3a8..182b77a0ff 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1186,8 +1186,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--9Ek0hoCL9XbhcSqy
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="0007-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 5/7] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--YZ5djTAD1cGYuMQK
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* [PATCH v24 05/10] fixups.patch
@ 2021-02-10 21:56 Robert Haas <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Robert Haas @ 2021-02-10 21:56 UTC (permalink / raw)
---
doc/src/sgml/ddl.sgml | 3 ---
doc/src/sgml/ref/create_table.sgml | 15 +++++++++++----
src/backend/access/common/detoast.c | 5 ++---
src/backend/access/compression/compress_lz4.c | 10 +++++-----
src/backend/executor/nodeModifyTable.c | 2 +-
src/include/nodes/execnodes.h | 4 ++--
6 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4d7ed698b9..1e9a4625cc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3762,9 +3762,6 @@ CREATE TABLE measurement (
<productname>PostgreSQL</productname>
tables (or, possibly, foreign tables). It is possible to specify a
tablespace and storage parameters for each partition separately.
- By default, each column in a partition inherits the compression method
- from parent table's column, however a different compression method can be
- set for each partition.
</para>
<para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 51a7a977a5..a4b297340f 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -997,10 +997,17 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<term><literal>COMPRESSION <replaceable class="parameter">compression_method</replaceable></literal></term>
<listitem>
<para>
- This sets the compression method for a column. The supported compression
- methods are <literal>pglz</literal> and <literal>lz4</literal>.
- <literal>lz4</literal> is available only if <literal>--with-lz4</literal>
- was used when building <productname>PostgreSQL</productname>. The default
+ The <literal>COMPRESSION</literal> clause sets the compression method
+ for a column. Compression is supported only for variable-width data
+ types, and is used only for columns whose storage type is main or
+ extended. (See <xref linkend="sql-altertable"/> for information on
+ column storage types.) Setting this property for a partitioned table
+ has no direct effect, because such tables have no storage of their own,
+ but the configured value is inherited by newly-created partitions.
+ The supported compression methods are <literal>pglz</literal> and
+ <literal>lz4</literal>. <literal>lz4</literal> is available only if
+ <literal>--with-lz4</literal> was used when building
+ <productname>PostgreSQL</productname>. The default
is <literal>pglz</literal>.
</para>
</listitem>
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index b78d49167b..95d5b1c12a 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -477,8 +477,8 @@ toast_get_compression_oid(struct varlena *attr)
return InvalidOid;
/*
- * Just fetch the toast compress header to know the compression method
- * in the compressed data.
+ * Fetch just enough of the value to examine the compression header,
+ * so that we can find out the compression method.
*/
attr = toast_fetch_datum_slice(attr, 0, VARHDRSZ_COMPRESS);
}
@@ -503,7 +503,6 @@ toast_get_compression_handler(struct varlena *attr)
cmid = TOAST_COMPRESS_METHOD(attr);
- /* Get the handler routines for the compression method */
switch (cmid)
{
case PGLZ_COMPRESSION_ID:
diff --git a/src/backend/access/compression/compress_lz4.c b/src/backend/access/compression/compress_lz4.c
index 1856cf7df7..3079eff7eb 100644
--- a/src/backend/access/compression/compress_lz4.c
+++ b/src/backend/access/compression/compress_lz4.c
@@ -23,7 +23,7 @@
/*
* lz4_cmcompress - compression routine for lz4 compression method
*
- * Compresses source into dest using the default strategy. Returns the
+ * Compresses source into dest using the LZ4 defaults. Returns the
* compressed varlena, or NULL if compression fails.
*/
static struct varlena *
@@ -42,8 +42,8 @@ lz4_cmcompress(const struct varlena *value)
valsize = VARSIZE_ANY_EXHDR(value);
/*
- * Get maximum size of the compressed data that lz4 compression may output
- * and allocate the memory for holding the compressed data and the header.
+ * Figure out the maximum possible size of the LZ4 output, add the bytes
+ * that will be needed for varlena overhead, and allocate that amount.
*/
max_size = LZ4_compressBound(valsize);
tmp = (struct varlena *) palloc(max_size + VARHDRSZ_COMPRESS);
@@ -83,10 +83,10 @@ lz4_cmdecompress(const struct varlena *value)
int32 rawsize;
struct varlena *result;
- /* allocate memory for holding the uncompressed data */
+ /* allocate memory for the uncompressed data */
result = (struct varlena *) palloc(VARRAWSIZE_4B_C(value) + VARHDRSZ);
- /* decompress data using lz4 routine */
+ /* decompress the data */
rawsize = LZ4_decompress_safe((char *) value + VARHDRSZ_COMPRESS,
VARDATA(result),
VARSIZE(value) - VARHDRSZ_COMPRESS,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index f77deee399..920d9dd0d5 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2117,7 +2117,7 @@ CompareCompressionMethodAndDecompress(TupleTableSlot *slot,
TupleTableSlot *newslot = *outslot;
/*
- * If the called has passed an invalid slot then create a new slot.
+ * If the caller has passed an invalid slot then create a new slot.
* Otherwise, just clear the existing tuple from the slot. This slot
* should be stored by the caller so that it can be reused for
* decompressing the subsequent tuples.
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18e8ecfd90..d8483c36b3 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1183,8 +1183,8 @@ typedef struct ModifyTableState
TupleTableSlot *mt_root_tuple_slot;
/*
- * Slot for storing the modified tuple, incase the target attribute's
- * compression method doesn't match with the source table.
+ * Slot for storing the modified tuple, in case the target attribute's
+ * compression method doesn't match that of the source table.
*/
TupleTableSlot *mt_decompress_tuple_slot;
--
2.17.0
--m51xatjYGsM+13rf
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v24-0006-alter-table-set-compression.patch"
^ permalink raw reply [nested|flat] 46+ messages in thread
* extension_control_path and "directory"
@ 2025-04-23 09:39 Christoph Berg <[email protected]>
0 siblings, 0 replies; 46+ messages in thread
From: Christoph Berg @ 2025-04-23 09:39 UTC (permalink / raw)
To: Peter Eisentraut <[email protected]>; +Cc: [email protected]; David E. Wheeler <[email protected]>
Re: Peter Eisentraut
> The new GUC extension_control_path specifies a path to look for
> extension control files. The default value is $system, which looks in
> the compiled-in location, as before.
Is the expectation that this also works for the extension "directory"?
semver is still failing because it's shipping its .sql files in a
separate directory:
2025-04-23 09:06:24.864 UTC [422345] myon@contrib_regression ERROR: could not open directory "/usr/share/postgresql/18/semver": No such file or directory
2025-04-23 09:06:24.864 UTC [422345] myon@contrib_regression STATEMENT: CREATE EXTENSION semver;
$ cat debian/postgresql-18-semver/usr/share/postgresql/18/extension/semver.control
# semver extension
comment = 'Semantic version data type'
default_version = '0.40.0'
directory = 'semver'
module_pathname = '$libdir/semver'
relocatable = true
$ ls debian/postgresql-18-semver/usr/share/postgresql/18/semver/
semver--0.10.0--0.11.0.sql semver--0.17.0--0.20.0.sql semver--0.30.0--0.31.0.sql semver--0.32.1--0.40.0.sql
semver--0.11.0--0.12.0.sql semver--0.20.0--0.21.0.sql semver--0.3.0--0.4.0.sql semver--0.40.0.sql
semver--0.12.0--0.13.0.sql semver--0.21.0--0.22.0.sql semver--0.31.0--0.31.1.sql semver--0.5.0--0.10.0.sql
semver--0.13.0--0.15.0.sql semver--0.2.1--0.2.4.sql semver--0.31.1--0.31.2.sql semver.sql
semver--0.15.0--0.16.0.sql semver--0.22.0--0.30.0.sql semver--0.31.2--0.32.0.sql semver--unpackaged--0.2.1.sql
semver--0.16.0--0.17.0.sql semver--0.2.4--0.3.0.sql semver--0.32.0--0.32.1.sql
Christoph
^ permalink raw reply [nested|flat] 46+ messages in thread
end of thread, other threads:[~2025-04-23 09:39 UTC | newest]
Thread overview: 46+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH 06/12] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 05/10] fixups.patch Robert Haas <[email protected]>
2021-02-10 21:56 [PATCH v24 5/7] fixups.patch Robert Haas <[email protected]>
2025-04-23 09:39 extension_control_path and "directory" Christoph Berg <[email protected]>
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox