public inbox for [email protected]
help / color / mirror / Atom feedFrom: Burd, Greg <[email protected]>
To: Matthias van de Meent <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: Expanding HOT updates for expression and partial indexes
Date: Mon, 17 Feb 2025 19:53:47 +0000
Message-ID: <[email protected]> (raw)
References: <[email protected]>
<CAEze2WjjOg+gE1VUZ2Omd-26MniaY6-UJghqzLZMHpVkDEUy8w@mail.gmail.com>
<[email protected]>
<CAEze2WgyAUtW64eP8uxZmHUy-RfBtuiKaUybvi=Jc3bwgg3g4Q@mail.gmail.com>
<[email protected]>
<CAEze2WjCJokQbBOQqK0qJFw0H=cu27XB=hrgQOhy9TQ=41RPmg@mail.gmail.com>
Matthias,
First off, I can't thank you enough for taking the time to review in detail the patch. I appreciate and value your time and excellent feedback.
Second, I think that I should admit to the fact that I've also been working on making PHOT functional again. I have it rebased against master, however it is still at the proof-of-concept phase and there are some larger issues to flesh out. One of the changes in this patch would have enabled that future with PHOT, specifically the bitmap as the method for conveying what indexes need updating.
That said, I agree that this patch should simply focus on expanding HOT to expression indexes and partial indexes. With that in mind I will return to the TU_UpdateIndexes approach, even though I'm not a fan of it, and later propose the bitmap approach (or something better) as part of PHOT if and when that's ready.
Changes v5 to v6:
* reverted to TU_UpdateIndexes rather than Bitmapset
* renamed ExecIndexesRequiringUpdates to ExecIndexesExpressionsWereNotUpdated
* ExecIndexesExpressionsWereNotUpdated returns bool, exits early if possible
* simple_update paths can be HOT once again
* removed efforts to determine the subset of updated summarizing indexes
* create filtered IndexInfo list in relcache containing only indexes with expressions
* now using index TupleDesc CompactAttributes for arguments to datum_is_equal() <- did I get this one right, I'm not sure it is what you had in mind
best.
-greg
> On Feb 15, 2025, at 5:49 AM, Matthias van de Meent <[email protected]> wrote:
>
> On Thu, 13 Feb 2025 at 19:46, Burd, Greg <[email protected]> wrote:
>
> -----
>
> I'm not a fan of how you replaced TU_UpdateIndexes with a bitmap. It
> seems unergonomic and a waste of performance.
>
> In HEAD, we don't do any expensive computations for the fast path of
> "indexed attribute updated" - at most we do the bitmap compare and
> then set a pointer. With this patch, the way we signal that is by
> allocating a bitmap of size O(n_indexes). That's potentially quite
> expensive (given 1000s of indexes), and definitely more expensive than
> only a pointer assignment.
Fair point. I'm not a fan of the TU_UpdateIndexes enum, but I appreciate your argument against the bitmapset. Under the conditions you describe (1000s of indexes) it could grow unwieldy and impact performance.
> In HEAD, we have a clear indication of which classes of indexes to
> update, with TU_UpdateIndexes. With this patch, we have to derive that
> from the (lack of) bits in the bitmap that might be output by the
> table_update procedure.
Yes, but... that "clear indication" is lacking the ability to convey more detailed information. It doesn't tell you which summarizing indexes really need updating just that as a result of being on the HOT path all summarizing indexes require updates.
> I think we can do with an additional parameter for which indexes would
> be updated (or store that info in the parameter which also will hold
> EState et al). I think it's cheaper that way, too - only when
> update_indexes could be TU_SUMMARIZING we might need the exact
> information for which indexes to insert new tuples into, and it only
> really needs to be sized to the number of summarizing indexes (usually
> small/nonexistent, but potentially huge).
Okay, yes with this patch we need only concern ourselves with all, none, or some subset of summarizing as before. I'll work on the opaque parameter next iteration.
> -----
>
> I think your patch design came from trying to include at least two
> distinct optimizations:
> 1) to make the HOT-or-not check include whether the expressions of
> indexes were updated, and
> 2) to only insert index tuples into indexes that got updated values
> when table_tuple_update returns update_indexes=TU_Summarizing.
It did. (1) for sure, but the second is more related to the PHOT work (as mentioned above). With that work almost all updates are on the HOT/PHOT path and so the bitmap of changed indexes is small. It would take an update of a table with 1000s of indexes where almost all those were modified to create a bitmap that was large, which certainly could (and somewhere likely does) exist, but it's not the common case (I'd imagine). In that case the work to update all those indexes will likely dwarf the work to build that bitmap, but I could be wrong.
But you're fundamentally right, I'm conflating two ideas and I shouldn't. I will focus the changes required for this idea without pulling in changes useful to a future ones.
> While they touch similar code (clearly seen here), I think those
> should be implemented in different patches. For (1), the current API
> surface is good enough when the EState is passed down. For (2), you'll
> indeed also need an additional argument we can use to fill with the
> right summarizing indexes, but I don't think that can nor should
> replace the function of TU_UpdateIndexes.
Okay, I'll combine the earlier v3 patch with the changes in v5. That should leave TU_UpdateIndexes in place and allow for HOT with expression indexes. I'll change the ExecIndexesRequiringUpdates() a bit (and rename it) so that it is just a boolean test for any index that spoils the HOT path and can exit early in that case potentially avoiding extra work.
> If you agree with my observation of those being distinct
> optimizations, could you split this patch into parts (but still within
> the same series) so that these are separately reviewable?
I agree, but I think that a single simple more focused patch will suffice.
> -----
>
> I notice that ExecIndexesRequiringUpdates() does work on all indexes,
> rather than just indexes relevant to this exact phase of checking. I
> think that is a waste of time, so if we sort the indexes in order of
> [hotblocking without expressions, hotblocking with expressions,
> summarizing], then (with stored start/end indexes) we can save time in
> cases where there are comparatively few of the types we're not going
> to look at.
If I plan on just having ExecIndexesRequiringUpdates() return a bool rather than a bitmap then sorting, or even just filtering the list of IndexInfo to only include indexes with expressions, makes sense. That way the only indexes in question in that function's loop will be those that may spoil the HOT path. When that list is length 0, we can skip the tests entirely.
> As an extreme example: we shouldn't do the (comparatively) expensive
> work evaluating expressions to determine which of 1000s of summarizing
> indexes has been updated when we're still not sure if we can apply HOT
> at all.
That makes sense, and your sorting idea would inform that kind of work. I'll keep that in mind if I reintroduce code that aims to only update changed summarized indexes.
> (Sidenote: Though, arguably, we could be smarter by skipping index
> insertions into unmodified summarizing indexes altogether regardless
> of HOT status, as long as the update is on the same page - but that's
> getting ahead of ourselves and not relevant to this discussion.)
>
> -----
>
> I noticed you've disabled any passing of "HOT or not" in the
> simple_update cases, and have done away with the various checks that
> are in place to prevent corruption. I don't think that's a great idea,
> it's quite likely to cause bugs.
Yes. I'll resurrect that.
> -----
>
> You're extracting type info from the opclass, to use in
> datum_image_eq(). Couldn't you instead use the index relation's
> TupleDesc and its stored attribute information instead? That saves us
> from having to do further catalog lookups during execution. I'm also
> fairly sure that that information is supposed to be a more accurate
> representation of attributes' expression output types than the
> opclass' type information (though, they probably should match).
I hadn't thought of that, I think it's a valid idea and I'll update accordingly. I think I understand what you are suggesting.
>
> -----
>
> The operations applied in ExecIndexesRequiringUpdates partially
> duplicate those done in index_unchanged_by_update. Can we (partially)
> unify this, and pass which indexes were updated through the IndexInfo,
> rather than the current bitmap?
I think I do that now, feel free to say otherwise. When the expression is checked in ExecIndexesExpressionsWereNotUpdated() I set:
/* Shortcut index_unchanged_by_update(), we know the answer. */ indexInfo->ii_CheckedUnchanged = true; indexInfo->ii_IndexUnchanged = !changed;
That prevents duplicate effort in index_unchanged_by_update().
> -----
>
> I don't see a good reason to add IndexInfo to Relation, by way of
> rd_indexInfoList. It seems like an ad-hoc way of passing data around,
> and I don't think that's the right way.
At one point I'd created a way to get this set via relcache, I will resurrect that approach but I'm not sure it is what you were hinting at. The current method avoids pulling a the lock on the index to build the list, but doing that once in relcache isn't horrible. Maybe you were suggesting using that opaque struct to pass around the list of IndexInfo? Let me know on this one if you had a specific idea. The swap I've made in v6 really just moves the IndexInfo list to a filtered list with a new name created in relcache.
Attachments:
[application/octet-stream] v6-0001-Expand-HOT-update-path-to-include-expression-and-.patch (86.8K, 2-v6-0001-Expand-HOT-update-path-to-include-expression-and-.patch)
download | inline diff:
From 47aa9640223d2b95dbb074ffc780fa109053191b Mon Sep 17 00:00:00 2001
From: Gregory Burd <[email protected]>
Date: Mon, 27 Jan 2025 13:28:59 -0500
Subject: [PATCH v6] Expand HOT update path to include expression and partial
indexes.
This patch extends the cases where HOT updates are possible in the heapam by
examining expression indexes and determining if indexed values where mutated
or not. Previously, any expression index on a column would disqualify it
from the HOT update path. Also examines partial indexes to see if the
values are within the predicate or not.
This is a modified application of a patch proposed on the pgsql-hackers list:
https://www.postgresql.org/message-id/flat/4d9928ee-a9e6-15f9-9c82-5981f13ffca6%40postgrespro.ru
applied: https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=c203d6cf8
reverted: https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=05f84605dbeb9cf8279a157234b24bbb706c5256
Signed-off-by: Greg Burd <[email protected]>
---
doc/src/sgml/ref/create_table.sgml | 17 +
doc/src/sgml/storage.sgml | 21 +
src/backend/access/common/reloptions.c | 12 +-
src/backend/access/heap/README.HOT | 43 +-
src/backend/access/heap/heapam.c | 43 +-
src/backend/access/heap/heapam_handler.c | 6 +-
src/backend/access/table/tableam.c | 2 +-
src/backend/catalog/index.c | 15 +
src/backend/executor/execIndexing.c | 200 ++++++
src/backend/executor/nodeModifyTable.c | 3 +-
src/backend/utils/cache/relcache.c | 181 +++++-
src/bin/psql/tab-complete.in.c | 2 +-
src/include/access/genam.h | 2 +-
src/include/access/heapam.h | 3 +-
src/include/access/tableam.h | 10 +-
src/include/executor/executor.h | 5 +
src/include/nodes/execnodes.h | 8 +
src/include/utils/rel.h | 14 +
src/include/utils/relcache.h | 2 +
.../regress/expected/heap_hot_updates.out | 586 ++++++++++++++++++
src/test/regress/parallel_schedule | 5 +
src/test/regress/sql/heap_hot_updates.sql | 440 +++++++++++++
22 files changed, 1560 insertions(+), 60 deletions(-)
create mode 100644 src/test/regress/expected/heap_hot_updates.out
create mode 100644 src/test/regress/sql/heap_hot_updates.sql
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 0a3e520f215..e29c9ea45a7 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1981,6 +1981,23 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
</listitem>
</varlistentry>
+ <varlistentry id="reloption-expression-checks" xreflabel="expression_checks">
+ <term><literal>expression_checks</literal> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>expression_checks</varname> storage parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Enables or disables evaulation of predicate expressions on partial
+ indexes or expressions used to define indexes during updates.
+ If <literal>true</literal>, then these expressions are evaluated during
+ updates to data within the heap relation against the old and new values
+ and then compared to determine if <acronym>HOT</acronym> updates are
+ allowable or not. The default value is <literal>true</literal>.
+ </para>
+ </listitem>
+
</variablelist>
</refsect2>
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 61250799ec0..f40ada9c989 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -1138,6 +1138,27 @@ data. Empty in ordinary tables.</entry>
</itemizedlist>
</para>
+ <para>
+ <acronym>HOT</acronym> updates can occur when the expression used to define
+ and index shows no changes to the indexed value. To determine this requires
+ that the expression be evaulated for the old and new values to be stored in
+ the index and then compared. This allows for <acronym>HOT</acronym> updates
+ when data indexed within JSONB columns is unchanged. To disable this
+ behavior and avoid the overhead of evaluating the expression during updates
+ set the <literal>expression_checks</literal> option to false for the table.
+ </para>
+
+ <para>
+ <acronym>HOT</acronym> updates can also occur when updated values are not
+ within the predicate of a partial index. However, <acronym>HOT</acronym>
+ updates are not possible when the updated value and the current value differ
+ with regards to the predicate. To determin this requires that the predicate
+ expression be evaluated for the old and new values to be stored in the index
+ and then compared. To disable this behavior and avoid the overhead of
+ evaluating the expression during updates set
+ the <literal>expression_checks</literal> option to false for the table.
+ </para>
+
<para>
You can increase the likelihood of sufficient page space for
<acronym>HOT</acronym> updates by decreasing a table's <link
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 59fb53e7707..c081611926e 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -166,6 +166,15 @@ static relopt_bool boolRelOpts[] =
},
true
},
+ {
+ {
+ "expression_checks",
+ "When disabled prevents checking expressions on indexes and predicates on partial indexes for changes that might influence heap-only tuple (HOT) updates.",
+ RELOPT_KIND_HEAP,
+ ShareUpdateExclusiveLock
+ },
+ true
+ },
/* list terminator */
{{NULL}}
};
@@ -1903,7 +1912,8 @@ default_reloptions(Datum reloptions, bool validate, relopt_kind kind)
{"vacuum_truncate", RELOPT_TYPE_BOOL,
offsetof(StdRdOptions, vacuum_truncate)},
{"vacuum_max_eager_freeze_failure_rate", RELOPT_TYPE_REAL,
- offsetof(StdRdOptions, vacuum_max_eager_freeze_failure_rate)}
+ offsetof(StdRdOptions, vacuum_max_eager_freeze_failure_rate)},
+ {"expression_checks", RELOPT_TYPE_BOOL, offsetof(StdRdOptions, expression_checks)}
};
return (bytea *) build_reloptions(reloptions, validate, kind,
diff --git a/src/backend/access/heap/README.HOT b/src/backend/access/heap/README.HOT
index 74e407f375a..48aab81fdf0 100644
--- a/src/backend/access/heap/README.HOT
+++ b/src/backend/access/heap/README.HOT
@@ -36,7 +36,7 @@ HOT solves this problem for two restricted but useful special cases:
First, where a tuple is repeatedly updated in ways that do not change
its indexed columns. (Here, "indexed column" means any column referenced
at all in an index definition, including for example columns that are
-tested in a partial-index predicate but are not stored in the index.)
+tested in a partial-index predicate, that has materially changed.)
Second, where the modified columns are only used in indexes that do not
contain tuple IDs, but maintain summaries of the indexed data by block.
@@ -133,18 +133,26 @@ Note: we can use a "dead" line pointer for any DELETEd tuple,
whether it was part of a HOT chain or not. This allows space reclamation
in advance of running VACUUM for plain DELETEs as well as HOT updates.
-The requirement for doing a HOT update is that indexes which point to
-the root line pointer (and thus need to be cleaned up by VACUUM when the
-tuple is dead) do not reference columns which are updated in that HOT
-chain. Summarizing indexes (such as BRIN) are assumed to have no
-references to individual tuples and thus are ignored when checking HOT
-applicability. The updated columns are checked at execution time by
-comparing the binary representation of the old and new values. We insist
-on bitwise equality rather than using datatype-specific equality routines.
-The main reason to avoid the latter is that there might be multiple
-notions of equality for a datatype, and we don't know exactly which one
-is relevant for the indexes at hand. We assume that bitwise equality
-guarantees equality for all purposes.
+The requirement for doing a HOT update is that indexes which point to the root
+line pointer (and thus need to be cleaned up by VACUUM when the tuple is dead)
+do not reference columns which are updated in that HOT chain.
+
+Summarizing indexes (such as BRIN) are assumed to have no references to
+individual tuples and thus are ignored when checking HOT applicability.
+
+Expressions on indexes are evaluated and the results are used when check for
+changes. This allows for the JSONB datatype to have HOT updates when the
+indexed portion of the document are not modified.
+
+Partial index expressions are evaluated, HOT updates are allowed when the
+updated index values do not satisfy the predicate.
+
+The updated columns are checked at execution time by comparing the binary
+representation of the old and new values. We insist on bitwise equality rather
+than using datatype-specific equality routines. The main reason to avoid the
+latter is that there might be multiple notions of equality for a datatype, and
+we don't know exactly which one is relevant for the indexes at hand. We assume
+that bitwise equality guarantees equality for all purposes.
If any columns that are included by non-summarizing indexes are updated,
the HOT optimization is not applied, and the new tuple is inserted into
@@ -152,9 +160,7 @@ all indexes of the table. If none of the updated columns are included in
the table's indexes, the HOT optimization is applied and no indexes are
updated. If instead the updated columns are only indexed by summarizing
indexes, the HOT optimization is applied, but the update is propagated to
-all summarizing indexes. (Realistically, we only need to propagate the
-update to the indexes that contain the updated values, but that is yet to
-be implemented.)
+the summarizing indexes that have updated values.
Abort Cases
-----------
@@ -477,8 +483,9 @@ Heap-only tuple
HOT-safe
A proposed tuple update is said to be HOT-safe if it changes
- none of the tuple's indexed columns. It will only become an
- actual HOT update if we can find room on the same page for
+ none of the tuple's indexed columns or if the changes remain
+ outside of a partial index's predicate. It will only become
+ an actual HOT update if we can find room on the same page for
the new tuple version.
HOT update
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index fa7935a0ed3..46ce824c4ea 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -3164,12 +3164,13 @@ TM_Result
heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
CommandId cid, Snapshot crosscheck, bool wait,
TM_FailureData *tmfd, LockTupleMode *lockmode,
- TU_UpdateIndexes *update_indexes)
+ TU_UpdateIndexes *update_indexes, struct EState *estate)
{
TM_Result result;
TransactionId xid = GetCurrentTransactionId();
Bitmapset *hot_attrs;
Bitmapset *sum_attrs;
+ Bitmapset *exp_attrs;
Bitmapset *key_attrs;
Bitmapset *id_attrs;
Bitmapset *interesting_attrs;
@@ -3246,6 +3247,8 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
INDEX_ATTR_BITMAP_HOT_BLOCKING);
sum_attrs = RelationGetIndexAttrBitmap(relation,
INDEX_ATTR_BITMAP_SUMMARIZED);
+ exp_attrs = RelationGetIndexAttrBitmap(relation,
+ INDEX_ATTR_BITMAP_EXPRESSION);
key_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_KEY);
id_attrs = RelationGetIndexAttrBitmap(relation,
INDEX_ATTR_BITMAP_IDENTITY_KEY);
@@ -3311,6 +3314,7 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
bms_free(hot_attrs);
bms_free(sum_attrs);
+ bms_free(exp_attrs);
bms_free(key_attrs);
bms_free(id_attrs);
/* modified_attrs not yet initialized */
@@ -3612,6 +3616,7 @@ l2:
bms_free(hot_attrs);
bms_free(sum_attrs);
+ bms_free(exp_attrs);
bms_free(key_attrs);
bms_free(id_attrs);
bms_free(modified_attrs);
@@ -3928,25 +3933,30 @@ l2:
if (newbuf == buffer)
{
+ bool expression_checks = RelationGetExpressionChecks(relation);
+
/*
* Since the new tuple is going into the same page, we might be able
- * to do a HOT update. Check if any of the index columns have been
- * changed.
+ * to do a HOT update. As a reminder, hot_attrs includes attributes
+ * used in expressions, but not attributes used by summarizing
+ * indexes.
*/
- if (!bms_overlap(modified_attrs, hot_attrs))
- {
+ if (!bms_overlap(modified_attrs, hot_attrs) ||
+ (expression_checks == true && estate != NULL && exp_attrs &&
+ bms_overlap(modified_attrs, exp_attrs) &&
+ ExecIndexesExpressionsWereNotUpdated(relation, modified_attrs,
+ estate, &oldtup, newtup)))
use_hot_update = true;
- /*
- * If none of the columns that are used in hot-blocking indexes
- * were updated, we can apply HOT, but we do still need to check
- * if we need to update the summarizing indexes, and update those
- * indexes if the columns were updated, or we may fail to detect
- * e.g. value bound changes in BRIN minmax indexes.
- */
- if (bms_overlap(modified_attrs, sum_attrs))
- summarized_update = true;
- }
+ /*
+ * If none of the columns that are used in hot-blocking indexes were
+ * updated, we can apply HOT, but we do still need to check if we need
+ * to update the summarizing indexes, and update those indexes if the
+ * columns were updated, or we may fail to detect e.g. value bound
+ * changes in BRIN minmax indexes.
+ */
+ if (use_hot_update && bms_overlap(modified_attrs, sum_attrs))
+ summarized_update = true;
}
else
{
@@ -4126,7 +4136,6 @@ l2:
heap_freetuple(old_key_tuple);
bms_free(hot_attrs);
- bms_free(sum_attrs);
bms_free(key_attrs);
bms_free(id_attrs);
bms_free(modified_attrs);
@@ -4413,7 +4422,7 @@ simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup,
result = heap_update(relation, otid, tup,
GetCurrentCommandId(true), InvalidSnapshot,
true /* wait for commit */ ,
- &tmfd, &lockmode, update_indexes);
+ &tmfd, &lockmode, update_indexes, NULL);
switch (result)
{
case TM_SelfModified:
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index c0bec014154..8e9ab892d73 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -312,8 +312,8 @@ heapam_tuple_delete(Relation relation, ItemPointer tid, CommandId cid,
static TM_Result
heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
CommandId cid, Snapshot snapshot, Snapshot crosscheck,
- bool wait, TM_FailureData *tmfd,
- LockTupleMode *lockmode, TU_UpdateIndexes *update_indexes)
+ bool wait, TM_FailureData *tmfd, LockTupleMode *lockmode,
+ TU_UpdateIndexes *update_indexes, EState *estate)
{
bool shouldFree = true;
HeapTuple tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
@@ -324,7 +324,7 @@ heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
tuple->t_tableOid = slot->tts_tableOid;
result = heap_update(relation, otid, tuple, cid, crosscheck, wait,
- tmfd, lockmode, update_indexes);
+ tmfd, lockmode, update_indexes, estate);
ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
/*
diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c
index e18a8f8250f..9feca8a296f 100644
--- a/src/backend/access/table/tableam.c
+++ b/src/backend/access/table/tableam.c
@@ -345,7 +345,7 @@ simple_table_tuple_update(Relation rel, ItemPointer otid,
GetCurrentCommandId(true),
snapshot, InvalidSnapshot,
true /* wait for commit */ ,
- &tmfd, &lockmode, update_indexes);
+ &tmfd, &lockmode, update_indexes, NULL);
switch (result)
{
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index cdabf780244..c28857a0943 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -2455,7 +2455,22 @@ BuildIndexInfo(Relation index)
/* fill in attribute numbers */
for (i = 0; i < numAtts; i++)
+ {
ii->ii_IndexAttrNumbers[i] = indexStruct->indkey.values[i];
+ ii->ii_IndexAttrs =
+ bms_add_member(ii->ii_IndexAttrs,
+ indexStruct->indkey.values[i] - FirstLowInvalidHeapAttributeNumber);
+
+ ii->ii_CompactAttr[i] = TupleDescCompactAttr(RelationGetDescr(index), i);
+ }
+
+ /* collect attributes used in the expression, if one is present */
+ if (ii->ii_Expressions)
+ pull_varattnos((Node *) ii->ii_Expressions, 1, &ii->ii_ExpressionAttrs);
+
+ /* collect attributes used in the predicate, if one is present */
+ if (ii->ii_Predicate)
+ pull_varattnos((Node *) ii->ii_Predicate, 1, &ii->ii_PredicateAttrs);
/* fetch exclusion constraint info if any */
if (indexStruct->indisexclusion)
diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c
index 7c87f012c30..7dce38dd08a 100644
--- a/src/backend/executor/execIndexing.c
+++ b/src/backend/executor/execIndexing.c
@@ -117,6 +117,8 @@
#include "utils/multirangetypes.h"
#include "utils/rangetypes.h"
#include "utils/snapmgr.h"
+#include "utils/datum.h"
+#include "utils/lsyscache.h"
/* waitMode argument to check_exclusion_or_unique_constraint() */
typedef enum
@@ -1089,6 +1091,9 @@ index_unchanged_by_update(ResultRelInfo *resultRelInfo, EState *estate,
if (hasexpression)
{
+ if (indexInfo->ii_IndexUnchanged)
+ return true;
+
indexInfo->ii_IndexUnchanged = false;
return false;
}
@@ -1166,3 +1171,198 @@ ExecWithoutOverlapsNotEmpty(Relation rel, NameData attname, Datum attval, char t
errmsg("empty WITHOUT OVERLAPS value found in column \"%s\" in relation \"%s\"",
NameStr(attname), RelationGetRelationName(rel))));
}
+
+/*
+ * Determine if any index with an expression requires updating.
+ *
+ * This function will review all indexes with expressions to determine if the
+ * update from old to new tuple requires that the index be updated. This is
+ * used to determine if a HOT update is possible or not.
+ *
+ * Returns true iff none of the expression indexes require updating due to the
+ * change from old to new tuple or when both the old and new tuples do not
+ * satisfy the predicate of the index.
+ */
+bool
+ExecIndexesExpressionsWereNotUpdated(Relation relation,
+ Bitmapset *modified_attrs,
+ EState *estate,
+ HeapTuple old_tuple,
+ HeapTuple new_tuple)
+{
+ ListCell *lc;
+ List *indexinfolist = RelationGetExprIndexInfoList(relation);
+ ExprContext *econtext = NULL;
+ TupleDesc tupledesc;
+ TupleTableSlot *old_tts = NULL;
+ TupleTableSlot *new_tts = NULL;
+ bool expression_checks = RelationGetExpressionChecks(relation);
+ bool changed = false;
+
+#ifndef USE_ASSERT_CHECKING
+
+ /*
+ * Assume the index is changed when we don't have an estate context to use
+ * or the reloption is disabled.
+ */
+ if (!expression_checks || estate == NULL)
+ return changed;
+#endif
+
+ Assert(expression_checks == true);
+ Assert(estate != NULL);
+
+ /*
+ * Examine expression and partial indexs on this relation relative to the
+ * changes between old and new tuples.
+ */
+ foreach(lc, indexinfolist)
+ {
+ IndexInfo *indexInfo = (IndexInfo *) lfirst(lc);
+
+ /*
+ * If this is a partial index it has a predicate, evaluate the
+ * expression to determine if we need to include it or not.
+ */
+ if (bms_overlap(indexInfo->ii_PredicateAttrs, modified_attrs))
+ {
+ ExprState *pstate;
+ bool old_tuple_qualifies,
+ new_tuple_qualifies;
+
+ /* Create these once, only if necessary, then reuse them. */
+ if (!econtext)
+ {
+ econtext = GetPerTupleExprContext(estate);
+ tupledesc = RelationGetDescr(relation);
+ old_tts = MakeSingleTupleTableSlot(tupledesc,
+ &TTSOpsHeapTuple);
+ new_tts = MakeSingleTupleTableSlot(tupledesc,
+ &TTSOpsHeapTuple);
+
+ ExecStoreHeapTuple(old_tuple, old_tts, InvalidBuffer);
+ ExecStoreHeapTuple(new_tuple, new_tts, InvalidBuffer);
+ }
+
+ pstate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
+
+ /*
+ * Here the term "qualifies" means "satisfies the predicate
+ * condition of the partial index".
+ */
+ econtext->ecxt_scantuple = old_tts;
+ old_tuple_qualifies = ExecQual(pstate, econtext);
+
+ econtext->ecxt_scantuple = new_tts;
+ new_tuple_qualifies = ExecQual(pstate, econtext);
+
+ /*
+ * If neither the old nor the new tuples satisfy the predicate we
+ * can be sure that this index doesn't need updating, continue to
+ * the next index.
+ */
+ if ((new_tuple_qualifies == false) && (old_tuple_qualifies == false))
+ continue;
+
+ /*
+ * If there is a transition between indexed and not indexed,
+ * that's enough to require that this index is updated.
+ */
+ if (new_tuple_qualifies != old_tuple_qualifies)
+ {
+ changed = true;
+ break;
+ }
+
+ /*
+ * Otherwise the old and new values exist in the index, but did
+ * they get updated? We don't yet know, so proceed with the next
+ * statement in the loop to find out.
+ */
+ }
+
+
+ /*
+ * Indexes with expressions may or may not have changed, it is
+ * impossible to know without exercising their expression and
+ * reviewing index tuple state for changes. This is a lot of work,
+ * but because all indexes on JSONB columns fall into this category it
+ * can be worth it to avoid index updates and remain on the HOT update
+ * path when possible.
+ */
+ if (bms_overlap(indexInfo->ii_ExpressionAttrs, modified_attrs))
+ {
+ Datum old_values[INDEX_MAX_KEYS];
+ bool old_isnull[INDEX_MAX_KEYS];
+ Datum new_values[INDEX_MAX_KEYS];
+ bool new_isnull[INDEX_MAX_KEYS];
+
+ /* Create these once, only if necessary, then reuse them. */
+ if (!econtext)
+ {
+ econtext = GetPerTupleExprContext(estate);
+ tupledesc = RelationGetDescr(relation);
+ old_tts = MakeSingleTupleTableSlot(tupledesc,
+ &TTSOpsHeapTuple);
+ new_tts = MakeSingleTupleTableSlot(tupledesc,
+ &TTSOpsHeapTuple);
+
+ ExecStoreHeapTuple(old_tuple, old_tts, InvalidBuffer);
+ ExecStoreHeapTuple(new_tuple, new_tts, InvalidBuffer);
+ }
+
+ indexInfo->ii_ExpressionsState = NIL;
+
+ econtext->ecxt_scantuple = old_tts;
+ FormIndexDatum(indexInfo,
+ old_tts,
+ estate,
+ old_values,
+ old_isnull);
+
+ econtext->ecxt_scantuple = new_tts;
+ FormIndexDatum(indexInfo,
+ new_tts,
+ estate,
+ new_values,
+ new_isnull);
+
+ for (int i = 0; i < indexInfo->ii_NumIndexKeyAttrs; i++)
+ {
+ if (old_isnull[i] != new_isnull[i])
+ {
+ changed = true;
+ break;
+ }
+ else if (!old_isnull[i])
+ {
+ int16 elmlen = indexInfo->ii_CompactAttr[i]->attlen;
+ bool elmbyval = indexInfo->ii_CompactAttr[i]->attbyval;
+
+ if (!datum_image_eq(old_values[i], new_values[i],
+ elmbyval, elmlen))
+ {
+ changed = true;
+ break;
+ }
+ }
+ }
+
+ if (changed)
+ {
+ /* Shortcut index_unchanged_by_update(), we know the answer. */
+ indexInfo->ii_CheckedUnchanged = true;
+ indexInfo->ii_IndexUnchanged = !changed;
+ break;
+ }
+ }
+ }
+
+ if (econtext)
+ {
+ ExecDropSingleTupleTableSlot(old_tts);
+ ExecDropSingleTupleTableSlot(new_tts);
+ }
+
+ return !changed;
+}
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index b0fe50075ad..d68f40cb998 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -2283,7 +2283,8 @@ lreplace:
estate->es_crosscheck_snapshot,
true /* wait for commit */ ,
&context->tmfd, &updateCxt->lockmode,
- &updateCxt->updateIndexes);
+ &updateCxt->updateIndexes,
+ estate);
return result;
}
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 398114373e9..b5e47b3521e 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -64,6 +64,7 @@
#include "catalog/pg_type.h"
#include "catalog/schemapg.h"
#include "catalog/storage.h"
+#include "catalog/index.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
#include "commands/trigger.h"
@@ -5188,6 +5189,128 @@ RelationGetIndexPredicate(Relation relation)
return result;
}
+ /*
+ * RelationGetExprIndexInfoList -- get a list of IndexInfo for expression
+ * indexes on this relation
+ */
+List *
+RelationGetExprIndexInfoList(Relation relation)
+{
+ ListCell *lc;
+ List *indexoidlist;
+ List *newindexoidlist;
+ List *result = NULL;
+ List *oldlist;
+ Oid relpkindex;
+ Oid relreplindex;
+ MemoryContext oldcxt;
+
+ if (relation->rd_iiexprlist)
+ return list_copy(relation->rd_iiexprlist);
+
+ /* Fast path if definitely no indexes */
+ if (!RelationGetForm(relation)->relhasindex)
+ return NIL;
+
+restart:
+ indexoidlist = RelationGetIndexList(relation);
+
+ /* Fall out if no indexes (but relhasindex was set) */
+ if (indexoidlist == NIL)
+ return NIL;
+
+ /*
+ * Copy the rd_pkindex and rd_replidindex values computed by
+ * RelationGetIndexList before proceeding. This is needed because a
+ * relcache flush could occur inside index_open below, resetting the
+ * fields managed by RelationGetIndexList. We need to do the work with
+ * stable values of these fields.
+ */
+ relpkindex = relation->rd_pkindex;
+ relreplindex = relation->rd_replidindex;
+
+ foreach(lc, indexoidlist)
+ {
+ Oid oid = lfirst_oid(lc);
+ Datum datum;
+ bool isnull;
+ Node *indexExpressions;
+ Node *indexPredicate;
+ Relation indexDesc;
+ IndexInfo *indexInfo;
+
+ /*
+ * Extract index expressions and index predicate. Note: Don't use
+ * RelationGetIndexExpressions()/RelationGetIndexPredicate(), because
+ * those might run constant expressions evaluation, which needs a
+ * snapshot, which we might not have here. (Also, it's probably more
+ * sound to collect the bitmaps before any transformations that might
+ * eliminate columns, but the practical impact of this is limited.)
+ */
+ indexDesc = index_open(oid, AccessShareLock);
+ datum = heap_getattr(indexDesc->rd_indextuple, Anum_pg_index_indexprs,
+ GetPgIndexDescriptor(), &isnull);
+ if (!isnull)
+ indexExpressions = stringToNode(TextDatumGetCString(datum));
+ else
+ indexExpressions = NULL;
+
+ datum = heap_getattr(indexDesc->rd_indextuple, Anum_pg_index_indpred,
+ GetPgIndexDescriptor(), &isnull);
+ if (!isnull)
+ indexPredicate = stringToNode(TextDatumGetCString(datum));
+ else
+ indexPredicate = NULL;
+
+ if (indexExpressions || indexPredicate)
+ {
+ oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+ indexInfo = BuildIndexInfo(indexDesc);
+ MemoryContextSwitchTo(oldcxt);
+ result = lappend(result, indexInfo);
+ }
+
+ index_close(indexDesc, AccessShareLock);
+ }
+
+ /*
+ * During one of the index_opens in the above loop, we might have received
+ * a relcache flush event on this relcache entry, which might have been
+ * signaling a change in the rel's index list. If so, we'd better start
+ * over to ensure we deliver up-to-date IndexInfo.
+ */
+ newindexoidlist = RelationGetIndexList(relation);
+ if (equal(indexoidlist, newindexoidlist) &&
+ relpkindex == relation->rd_pkindex &&
+ relreplindex == relation->rd_replidindex)
+ {
+ /* Still the same index set, so proceed */
+ list_free(newindexoidlist);
+ list_free(indexoidlist);
+ }
+ else
+ {
+ /* Gotta do it over ... might as well not leak memory */
+ list_free(newindexoidlist);
+ list_free(indexoidlist);
+ list_free(result);
+
+ goto restart;
+ }
+
+ /* Now save a copy of the completed list in the relcache entry. */
+ oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+ oldlist = relation->rd_iiexprlist;
+ relation->rd_iiexprlist = list_copy(result);
+ MemoryContextSwitchTo(oldcxt);
+
+ /* Don't leak the old list, if there is one */
+ if (oldlist)
+ list_free(oldlist);
+
+ return result;
+}
+
/*
* RelationGetIndexAttrBitmap -- get a bitmap of index attribute numbers
*
@@ -5229,7 +5352,11 @@ RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
Bitmapset *pkindexattrs; /* columns in the primary index */
Bitmapset *idindexattrs; /* columns in the replica identity */
Bitmapset *hotblockingattrs; /* columns with HOT blocking indexes */
+ Bitmapset *hotblockingexprattrs; /* as above, but only those in
+ * expressions */
Bitmapset *summarizedattrs; /* columns with summarizing indexes */
+ Bitmapset *summarizedexprattrs; /* as above, but only those in
+ * expressions */
List *indexoidlist;
List *newindexoidlist;
Oid relpkindex;
@@ -5252,6 +5379,8 @@ RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
return bms_copy(relation->rd_hotblockingattr);
case INDEX_ATTR_BITMAP_SUMMARIZED:
return bms_copy(relation->rd_summarizedattr);
+ case INDEX_ATTR_BITMAP_EXPRESSION:
+ return bms_copy(relation->rd_expressionattr);
default:
elog(ERROR, "unknown attrKind %u", attrKind);
}
@@ -5295,7 +5424,9 @@ restart:
pkindexattrs = NULL;
idindexattrs = NULL;
hotblockingattrs = NULL;
+ hotblockingexprattrs = NULL;
summarizedattrs = NULL;
+ summarizedexprattrs = NULL;
foreach(l, indexoidlist)
{
Oid indexOid = lfirst_oid(l);
@@ -5309,6 +5440,7 @@ restart:
bool isPK; /* primary key */
bool isIDKey; /* replica identity index */
Bitmapset **attrs;
+ Bitmapset **exprattrs;
indexDesc = index_open(indexOid, AccessShareLock);
@@ -5352,14 +5484,20 @@ restart:
* decide which bitmap we'll update in the following loop.
*/
if (indexDesc->rd_indam->amsummarizing)
+ {
attrs = &summarizedattrs;
+ exprattrs = &summarizedexprattrs;
+ }
else
+ {
attrs = &hotblockingattrs;
+ exprattrs = &hotblockingexprattrs;
+ }
/* Collect simple attribute references */
for (i = 0; i < indexDesc->rd_index->indnatts; i++)
{
- int attrnum = indexDesc->rd_index->indkey.values[i];
+ int attridx = indexDesc->rd_index->indkey.values[i];
/*
* Since we have covering indexes with non-key columns, we must
@@ -5375,30 +5513,28 @@ restart:
* key or identity key. Hence we do not include them into
* uindexattrs, pkindexattrs and idindexattrs bitmaps.
*/
- if (attrnum != 0)
+ if (attridx != 0)
{
- *attrs = bms_add_member(*attrs,
- attrnum - FirstLowInvalidHeapAttributeNumber);
+ AttrNumber attrnum = attridx - FirstLowInvalidHeapAttributeNumber;
+
+ *attrs = bms_add_member(*attrs, attrnum);
if (isKey && i < indexDesc->rd_index->indnkeyatts)
- uindexattrs = bms_add_member(uindexattrs,
- attrnum - FirstLowInvalidHeapAttributeNumber);
+ uindexattrs = bms_add_member(uindexattrs, attrnum);
if (isPK && i < indexDesc->rd_index->indnkeyatts)
- pkindexattrs = bms_add_member(pkindexattrs,
- attrnum - FirstLowInvalidHeapAttributeNumber);
+ pkindexattrs = bms_add_member(pkindexattrs, attrnum);
if (isIDKey && i < indexDesc->rd_index->indnkeyatts)
- idindexattrs = bms_add_member(idindexattrs,
- attrnum - FirstLowInvalidHeapAttributeNumber);
+ idindexattrs = bms_add_member(idindexattrs, attrnum);
}
}
/* Collect all attributes used in expressions, too */
- pull_varattnos(indexExpressions, 1, attrs);
+ pull_varattnos(indexExpressions, 1, exprattrs);
/* Collect all attributes in the index predicate, too */
- pull_varattnos(indexPredicate, 1, attrs);
+ pull_varattnos(indexPredicate, 1, exprattrs);
index_close(indexDesc, AccessShareLock);
}
@@ -5427,11 +5563,27 @@ restart:
bms_free(pkindexattrs);
bms_free(idindexattrs);
bms_free(hotblockingattrs);
+ bms_free(hotblockingexprattrs);
bms_free(summarizedattrs);
+ bms_free(summarizedexprattrs);
goto restart;
}
+ /* {expression-only columns} = {expression columns} - {direct columns} */
+ hotblockingexprattrs = bms_del_members(hotblockingexprattrs,
+ hotblockingattrs);
+ /* {hot-blocking columns} = {direct columns} + {expression-only columns} */
+ hotblockingattrs = bms_add_members(hotblockingattrs,
+ hotblockingexprattrs);
+
+ /* {summarized-only columns} = {summarized columns} - {direct columns} */
+ summarizedexprattrs = bms_del_members(summarizedexprattrs,
+ summarizedattrs);
+ /* {summarized columns} = {direct columns} + {summarized-only columns} */
+ summarizedattrs = bms_add_members(summarizedattrs,
+ summarizedexprattrs);
+
/* Don't leak the old values of these bitmaps, if any */
relation->rd_attrsvalid = false;
bms_free(relation->rd_keyattr);
@@ -5444,6 +5596,8 @@ restart:
relation->rd_hotblockingattr = NULL;
bms_free(relation->rd_summarizedattr);
relation->rd_summarizedattr = NULL;
+ bms_free(relation->rd_expressionattr);
+ relation->rd_expressionattr = NULL;
/*
* Now save copies of the bitmaps in the relcache entry. We intentionally
@@ -5458,6 +5612,7 @@ restart:
relation->rd_idattr = bms_copy(idindexattrs);
relation->rd_hotblockingattr = bms_copy(hotblockingattrs);
relation->rd_summarizedattr = bms_copy(summarizedattrs);
+ relation->rd_expressionattr = bms_copy(hotblockingexprattrs);
relation->rd_attrsvalid = true;
MemoryContextSwitchTo(oldcxt);
@@ -5474,6 +5629,8 @@ restart:
return hotblockingattrs;
case INDEX_ATTR_BITMAP_SUMMARIZED:
return summarizedattrs;
+ case INDEX_ATTR_BITMAP_EXPRESSION:
+ return hotblockingexprattrs;
default:
elog(ERROR, "unknown attrKind %u", attrKind);
return NULL;
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index eb8bc128720..f0a8286a25b 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -2992,7 +2992,7 @@ match_previous_words(int pattern_id,
COMPLETE_WITH("(");
/* ALTER TABLESPACE <foo> SET|RESET ( */
else if (Matches("ALTER", "TABLESPACE", MatchAny, "SET|RESET", "("))
- COMPLETE_WITH("seq_page_cost", "random_page_cost",
+ COMPLETE_WITH("seq_page_cost", "random_page_cost", "expression_checks",
"effective_io_concurrency", "maintenance_io_concurrency");
/* ALTER TEXT SEARCH */
diff --git a/src/include/access/genam.h b/src/include/access/genam.h
index 1be8739573f..91af1e8238d 100644
--- a/src/include/access/genam.h
+++ b/src/include/access/genam.h
@@ -194,7 +194,7 @@ extern bool index_can_return(Relation indexRelation, int attno);
extern RegProcedure index_getprocid(Relation irel, AttrNumber attnum,
uint16 procnum);
extern FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attnum,
- uint16 procnum);
+ uint16 procnum);
extern void index_store_float8_orderby_distances(IndexScanDesc scan,
Oid *orderByTypes,
IndexOrderByDistance *distances,
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 1640d9c32f7..e12da1934e9 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -21,6 +21,7 @@
#include "access/skey.h"
#include "access/table.h" /* for backward compatibility */
#include "access/tableam.h"
+#include "executor/executor.h"
#include "nodes/lockoptions.h"
#include "nodes/primnodes.h"
#include "storage/bufpage.h"
@@ -339,7 +340,7 @@ extern TM_Result heap_update(Relation relation, ItemPointer otid,
HeapTuple newtup,
CommandId cid, Snapshot crosscheck, bool wait,
struct TM_FailureData *tmfd, LockTupleMode *lockmode,
- TU_UpdateIndexes *update_indexes);
+ TU_UpdateIndexes *update_indexes, struct EState *estate);
extern TM_Result heap_lock_tuple(Relation relation, HeapTuple tuple,
CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy,
bool follow_updates,
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h
index 131c050c15f..62ed6592b85 100644
--- a/src/include/access/tableam.h
+++ b/src/include/access/tableam.h
@@ -38,6 +38,7 @@ struct IndexInfo;
struct SampleScanState;
struct VacuumParams;
struct ValidateIndexState;
+struct EState;
/*
* Bitmask values for the flags argument to the scan_begin callback.
@@ -550,7 +551,8 @@ typedef struct TableAmRoutine
bool wait,
TM_FailureData *tmfd,
LockTupleMode *lockmode,
- TU_UpdateIndexes *update_indexes);
+ TU_UpdateIndexes *update_indexes,
+ struct EState *estate);
/* see table_tuple_lock() for reference about parameters */
TM_Result (*tuple_lock) (Relation rel,
@@ -1541,12 +1543,12 @@ static inline TM_Result
table_tuple_update(Relation rel, ItemPointer otid, TupleTableSlot *slot,
CommandId cid, Snapshot snapshot, Snapshot crosscheck,
bool wait, TM_FailureData *tmfd, LockTupleMode *lockmode,
- TU_UpdateIndexes *update_indexes)
+ TU_UpdateIndexes *update_indexes, struct EState *estate)
{
return rel->rd_tableam->tuple_update(rel, otid, slot,
cid, snapshot, crosscheck,
- wait, tmfd,
- lockmode, update_indexes);
+ wait, tmfd, lockmode,
+ update_indexes, estate);
}
/*
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 30e2a82346f..343d04fff57 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -661,6 +661,11 @@ extern void check_exclusion_constraint(Relation heap, Relation index,
ItemPointer tupleid,
const Datum *values, const bool *isnull,
EState *estate, bool newIndex);
+extern bool ExecIndexesExpressionsWereNotUpdated(Relation relation,
+ Bitmapset *modified_attrs,
+ EState *estate,
+ HeapTuple old_tuple,
+ HeapTuple new_tuple);
/*
* prototypes from functions in execReplication.c
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 2625d7e8222..9bfdd0d1464 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -159,12 +159,15 @@ typedef struct ExprState
*
* NumIndexAttrs total number of columns in this index
* NumIndexKeyAttrs number of key columns in index
+ * IndexAttrs bitmap of index attributes
* IndexAttrNumbers underlying-rel attribute numbers used as keys
* (zeroes indicate expressions). It also contains
* info about included columns.
* Expressions expr trees for expression entries, or NIL if none
+ * ExpressionAttrs bitmap of attributes used within the expression
* ExpressionsState exec state for expressions, or NIL if none
* Predicate partial-index predicate, or NIL if none
+ * PredicateAttrs bitmap of attributes used within the predicate
* PredicateState exec state for predicate, or NIL if none
* ExclusionOps Per-column exclusion operators, or NULL if none
* ExclusionProcs Underlying function OIDs for ExclusionOps
@@ -183,6 +186,7 @@ typedef struct ExprState
* ParallelWorkers # of workers requested (excludes leader)
* Am Oid of index AM
* AmCache private cache area for index AM
+ * OpClassDataTypes operator class data types
* Context memory context holding this IndexInfo
*
* ii_Concurrent, ii_BrokenHotChain, and ii_ParallelWorkers are used only
@@ -194,10 +198,14 @@ typedef struct IndexInfo
NodeTag type;
int ii_NumIndexAttrs; /* total number of columns in index */
int ii_NumIndexKeyAttrs; /* number of key columns in index */
+ Bitmapset *ii_IndexAttrs;
AttrNumber ii_IndexAttrNumbers[INDEX_MAX_KEYS];
+ CompactAttribute *ii_CompactAttr[INDEX_MAX_KEYS];
List *ii_Expressions; /* list of Expr */
+ Bitmapset *ii_ExpressionAttrs;
List *ii_ExpressionsState; /* list of ExprState */
List *ii_Predicate; /* list of Expr */
+ Bitmapset *ii_PredicateAttrs;
ExprState *ii_PredicateState;
Oid *ii_ExclusionOps; /* array with one entry per column */
Oid *ii_ExclusionProcs; /* array with one entry per column */
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index db3e504c3d2..3eba254a366 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -164,6 +164,11 @@ typedef struct RelationData
Bitmapset *rd_idattr; /* included in replica identity index */
Bitmapset *rd_hotblockingattr; /* cols blocking HOT update */
Bitmapset *rd_summarizedattr; /* cols indexed by summarizing indexes */
+ Bitmapset *rd_expressionattr; /* indexed cols referenced by expressions */
+
+ /* data managed by RelationGetExprIndexInfoList: */
+ List *rd_iiexprlist; /* list of IndexInfo for indexes with
+ * expressions */
PublicationDesc *rd_pubdesc; /* publication descriptor, or NULL */
@@ -344,6 +349,7 @@ typedef struct StdRdOptions
int parallel_workers; /* max number of parallel workers */
StdRdOptIndexCleanup vacuum_index_cleanup; /* controls index vacuuming */
bool vacuum_truncate; /* enables vacuum to truncate a relation */
+ bool expression_checks; /* use expression to checks for changes */
/*
* Fraction of pages in a relation that vacuum can eagerly scan and fail
@@ -405,6 +411,14 @@ typedef struct StdRdOptions
((relation)->rd_options ? \
((StdRdOptions *) (relation)->rd_options)->parallel_workers : (defaultpw))
+/*
+ * RelationGetExpressionChecks
+ * Returns the relation's expression_checks reloption setting.
+ */
+#define RelationGetExpressionChecks(relation) \
+ ((relation)->rd_options ? \
+ ((StdRdOptions *) (relation)->rd_options)->expression_checks : true)
+
/* ViewOptions->check_option values */
typedef enum ViewOptCheckOption
{
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index a7c55db339e..56524a73399 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -52,6 +52,7 @@ extern List *RelationGetIndexExpressions(Relation relation);
extern List *RelationGetDummyIndexExpressions(Relation relation);
extern List *RelationGetIndexPredicate(Relation relation);
extern bytea **RelationGetIndexAttOptions(Relation relation, bool copy);
+extern List *RelationGetExprIndexInfoList(Relation relation);
/*
* Which set of columns to return by RelationGetIndexAttrBitmap.
@@ -63,6 +64,7 @@ typedef enum IndexAttrBitmapKind
INDEX_ATTR_BITMAP_IDENTITY_KEY,
INDEX_ATTR_BITMAP_HOT_BLOCKING,
INDEX_ATTR_BITMAP_SUMMARIZED,
+ INDEX_ATTR_BITMAP_EXPRESSION,
} IndexAttrBitmapKind;
extern Bitmapset *RelationGetIndexAttrBitmap(Relation relation,
diff --git a/src/test/regress/expected/heap_hot_updates.out b/src/test/regress/expected/heap_hot_updates.out
new file mode 100644
index 00000000000..2ad6e5418e9
--- /dev/null
+++ b/src/test/regress/expected/heap_hot_updates.out
@@ -0,0 +1,586 @@
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This table will have two columns and two indexes, one on the primary key
+-- id and one on the expression (info->>'name'). That means that the indexed
+-- attributes are 'id' and 'info'.
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name'));
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+-- Disable expression checks.
+ALTER TABLE keyvalue SET (expression_checks = false);
+SELECT reloptions FROM pg_class WHERE relname = 'keyvalue';
+ reloptions
+---------------------------
+ {expression_checks=false}
+(1 row)
+
+-- While the indexed attribute "name" is unchanged we've disabled expression
+-- checks so this update should not go HOT as the system can't determine if
+-- the indexed attribute has changed without evaluating the expression.
+update keyvalue set info='{"name": "john", "data": "something else"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 0 row
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+-- Re-enable expression checks.
+ALTER TABLE keyvalue SET (expression_checks = true);
+SELECT reloptions FROM pg_class WHERE relname = 'keyvalue';
+ reloptions
+--------------------------
+ {expression_checks=true}
+(1 row)
+
+-- The indexed attribute "name" with value "john" is unchanged, expect a HOT update.
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 1 row
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- The following update changes the indexed attribute "name", this should not be a HOT update.
+update keyvalue set info='{"name": "smith", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Now, this update does not change the indexed attribute "name" from "smith", this should be HOT.
+update keyvalue set info='{"name": "smith", "data": "some more data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 2 rows now
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 2
+(1 row)
+
+drop table keyvalue;
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This table is the same as the previous one but it has a third index. The
+-- index 'colindex' isn't an expression index, it indexes the entire value
+-- in the info column. There are still only two indexed attributes for this
+-- relation, the same two as before. The presence of an index on the entire
+-- value of the info column should prevent HOT updates for any updates to any
+-- portion of JSONB content in that column.
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name'));
+create index colindex on keyvalue(info);
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+-- This update doesn't change the value of the expression index, but it does
+-- change the content of the info column and so should not be HOT because the
+-- indexed value changed as a result of the update.
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 0 rows
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+drop table keyvalue;
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- The table has one column docs and two indexes. They are both expression
+-- indexes referencing the same column attribute (docs) but one is a partial
+-- index.
+CREATE TABLE ex (docs JSONB) WITH (fillfactor = 60);
+INSERT INTO ex (docs) VALUES ('{"a": 0, "b": 0}');
+INSERT INTO ex (docs) SELECT jsonb_build_object('b', n) FROM generate_series(100, 10000) as n;
+CREATE INDEX idx_ex_a ON ex ((docs->>'a'));
+CREATE INDEX idx_ex_b ON ex ((docs->>'b')) WHERE (docs->>'b')::numeric > 9;
+-- We're using BTREE indexes and for this test we want to make sure that they remain
+-- in sync with changes to our relation. Force the choice of index scans below so
+-- that we know we're checking the index's understanding of what values should be
+-- in the index or not.
+SET SESSION enable_seqscan = OFF;
+SET SESSION enable_bitmapscan = OFF;
+-- Leave 'a' unchanged but modify 'b' to a value outside of the index predicate.
+-- This should be a HOT update because neither index is changed.
+UPDATE ex SET docs = jsonb_build_object('a', 0, 'b', 1) WHERE (docs->>'a')::numeric = 0;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 row
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Let's check to make sure that the index does not contain a value for 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ QUERY PLAN
+--------------------------------------------------------------
+ Index Scan using idx_ex_b on ex
+ Filter: (((docs ->> 'b'::text))::numeric < '100'::numeric)
+(2 rows)
+
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ docs
+------
+(0 rows)
+
+-- Leave 'a' unchanged but modify 'b' to a value within the index predicate.
+-- This represents a change for field 'b' from unindexed to indexed and so
+-- this should not take the HOT path.
+UPDATE ex SET docs = jsonb_build_object('a', 0, 'b', 10) WHERE (docs->>'a')::numeric = 0;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Let's check to make sure that the index contains the new value of 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ QUERY PLAN
+--------------------------------------------------------------
+ Index Scan using idx_ex_b on ex
+ Filter: (((docs ->> 'b'::text))::numeric < '100'::numeric)
+(2 rows)
+
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ docs
+-------------------
+ {"a": 0, "b": 10}
+(1 row)
+
+-- This update modifies the value of 'a', an indexed field, so it also cannot
+-- be a HOT update.
+UPDATE ex SET docs = jsonb_build_object('a', 1, 'b', 10) WHERE (docs->>'b')::numeric = 10;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- This update changes both 'a' and 'b' to new values that require index updates,
+-- this cannot use the HOT path.
+UPDATE ex SET docs = jsonb_build_object('a', 2, 'b', 12) WHERE (docs->>'b')::numeric = 10;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Let's check to make sure that the index contains the new value of 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ QUERY PLAN
+--------------------------------------------------------------
+ Index Scan using idx_ex_b on ex
+ Filter: (((docs ->> 'b'::text))::numeric < '100'::numeric)
+(2 rows)
+
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ docs
+-------------------
+ {"a": 2, "b": 12}
+(1 row)
+
+-- This update changes 'b' to a value outside its predicate requiring that
+-- we remove it from the index. That's a transition that can't be done
+-- during a HOT update.
+UPDATE ex SET docs = jsonb_build_object('a', 2, 'b', 1) WHERE (docs->>'b')::numeric = 12;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Let's check to make sure that the index no longer contains the value of 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ QUERY PLAN
+--------------------------------------------------------------
+ Index Scan using idx_ex_b on ex
+ Filter: (((docs ->> 'b'::text))::numeric < '100'::numeric)
+(2 rows)
+
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+ docs
+------
+(0 rows)
+
+-- Disable expression checks.
+ALTER TABLE ex SET (expression_checks = false);
+SELECT reloptions FROM pg_class WHERE relname = 'ex';
+ reloptions
+-----------------------------------------
+ {fillfactor=60,expression_checks=false}
+(1 row)
+
+-- This update changes 'b' to a value within its predicate just like it
+-- previous value, which would allow for a HOT update but with expression
+-- checks disabled we can't determine that so this should not be a HOT update.
+UPDATE ex SET docs = jsonb_build_object('a', 2, 'b', 2) WHERE (docs->>'b')::numeric = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Let's make sure we're recording HOT updates for our 'ex' relation properly in the system
+-- table pg_stat_user_tables. Note that statistics are stored within a transaction context
+-- first (xact) and then later into the global statistics for a relation, so first we need
+-- to ensure pending stats are flushed.
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT
+ c.relname AS table_name,
+ -- Transaction statistics
+ pg_stat_get_xact_tuples_updated(c.oid) AS xact_updates,
+ pg_stat_get_xact_tuples_hot_updated(c.oid) AS xact_hot_updates,
+ ROUND((
+ pg_stat_get_xact_tuples_hot_updated(c.oid)::float /
+ NULLIF(pg_stat_get_xact_tuples_updated(c.oid), 0) * 100
+ )::numeric, 2) AS xact_hot_update_percentage,
+ -- Cumulative statistics
+ s.n_tup_upd AS total_updates,
+ s.n_tup_hot_upd AS hot_updates,
+ ROUND((
+ s.n_tup_hot_upd::float /
+ NULLIF(s.n_tup_upd, 0) * 100
+ )::numeric, 2) AS total_hot_update_percentage
+FROM pg_class c
+LEFT JOIN pg_stat_user_tables s ON c.relname = s.relname
+WHERE c.relname = 'ex'
+AND c.relnamespace = 'public'::regnamespace;
+ table_name | xact_updates | xact_hot_updates | xact_hot_update_percentage | total_updates | hot_updates | total_hot_update_percentage
+------------+--------------+------------------+----------------------------+---------------+-------------+-----------------------------
+ ex | 0 | 0 | | 6 | 1 | 16.67
+(1 row)
+
+-- expect: 5 xact updates with 1 xact hot update and no cumulative updates as yet
+SET SESSION enable_seqscan = ON;
+SET SESSION enable_bitmapscan = ON;
+DROP TABLE ex;
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This table has a single column 'email' and a unique constraint on it that
+-- should preclude HOT updates.
+CREATE TABLE users (
+ user_id serial primary key,
+ name VARCHAR(255) NOT NULL,
+ email VARCHAR(255) NOT NULL,
+ EXCLUDE USING btree (lower(email) WITH =)
+);
+-- Add some data to the table and then update it in ways that should and should
+-- not be HOT updates.
+INSERT INTO users (name, email) VALUES
+('user1', '[email protected]'),
+('user2', '[email protected]'),
+('taken', '[email protected]'),
+('you', '[email protected]'),
+('taken', '[email protected]');
+-- Should fail because of the unique constraint on the email column.
+UPDATE users SET email = '[email protected]' WHERE email = '[email protected]';
+ERROR: conflicting key value violates exclusion constraint "users_lower_excl"
+DETAIL: Key (lower(email::text))=([email protected]) conflicts with existing key (lower(email::text))=([email protected]).
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 0 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+-- Should succeed because the email column is not being updated and should go HOT.
+UPDATE users SET name = 'foo' WHERE email = '[email protected]';
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 1 a single new HOT update
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Create a partial index on the email column, updates
+CREATE INDEX idx_users_email_no_example ON users (lower(email)) WHERE lower(email) LIKE '%@example.com%';
+-- An update that changes the email column but not the indexed portion of it and falls outside the constraint.
+-- Shouldn't be a HOT update because of the exclusion constraint.
+UPDATE users SET email = '[email protected]' WHERE name = 'you';
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- An update that changes the email column but not the indexed portion of it and falls within the constraint.
+-- Again, should fail constraint and fail to be a HOT update.
+UPDATE users SET email = '[email protected]' WHERE name = 'you';
+ERROR: conflicting key value violates exclusion constraint "users_lower_excl"
+DETAIL: Key (lower(email::text))=([email protected]) conflicts with existing key (lower(email::text))=([email protected]).
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 1 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+DROP TABLE users;
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- Another test of constraints spoiling HOT updates, this time with a range.
+CREATE TABLE events (
+ id serial primary key,
+ name VARCHAR(255) NOT NULL,
+ event_time tstzrange,
+ constraint no_screening_time_overlap exclude using gist (
+ event_time WITH &&
+ )
+);
+-- Add two non-overlapping events.
+INSERT INTO events (id, event_time, name)
+VALUES
+ (1, '["2023-01-01 19:00:00", "2023-01-01 20:45:00"]', 'event1'),
+ (2, '["2023-01-01 21:00:00", "2023-01-01 21:45:00"]', 'event2');
+-- Update the first event to overlap with the second, should fail the constraint and not be HOT.
+UPDATE events SET event_time = '["2023-01-01 20:00:00", "2023-01-01 21:45:00"]' WHERE id = 1;
+ERROR: conflicting key value violates exclusion constraint "no_screening_time_overlap"
+DETAIL: Key (event_time)=(["Sun Jan 01 20:00:00 2023 PST","Sun Jan 01 21:45:00 2023 PST"]) conflicts with existing key (event_time)=(["Sun Jan 01 21:00:00 2023 PST","Sun Jan 01 21:45:00 2023 PST"]).
+SELECT pg_stat_get_xact_tuples_hot_updated('events'::regclass); -- expect: 0 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+-- Update the first event to not overlap with the second, again not HOT due to the constraint.
+UPDATE events SET event_time = '["2023-01-01 22:00:00", "2023-01-01 22:45:00"]' WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('events'::regclass); -- expect: 0 no new HOT updates
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+-- Update the first event to not overlap with the second, this time we're HOT because we don't overlap with the constraint.
+UPDATE events SET name = 'new name here' WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('events'::regclass); -- expect: 1 one new HOT update
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+DROP TABLE events;
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- A test to ensure that summarizing indexes are not updated when they don't
+-- change, but are updated when they do while not prefent HOT updates.
+CREATE TABLE ex (att1 JSONB, att2 text) WITH (fillfactor = 60);
+CREATE INDEX expression ON ex USING btree((att1->'data'));
+CREATE INDEX summarizing ON ex USING BRIN(att2);
+INSERT INTO ex VALUES ('{"data": []}', 'nothing special');
+-- Update the unindexed value of att1, this should be a HOT update and not
+-- update the summarizing index.
+UPDATE ex SET att1 = att1 || '{"status": "checkmate"}';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 one new HOT update
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Update the indexed value of att2, a summarized value, this is a summarized
+-- only update and should use the HOT path while still triggering an update to
+-- the summarizing BRIN index.
+UPDATE ex SET att2 = 'special indeed';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 2 one new HOT update
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 2
+(1 row)
+
+-- Update to att1 doesn't change the indexed value while the update to att2 does,
+-- this again is a summarized only update and should use the HOT path as well as
+-- trigger an update to the BRIN index.
+UPDATE ex SET att1 = att1 || '{"status": "checkmate!"}', att2 = 'special, so special';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 3 one new HOT update
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 3
+(1 row)
+
+-- This updates both indexes, the expression index on att1 and the summarizing
+-- index on att2. This should not be a HOT update because there are modified
+-- indexes and only some are summarized, not all. This should force all
+-- indexes to be updated.
+UPDATE ex SET att1 = att1 || '{"data": [1,2,3]}', att2 = 'do you want to play a game?';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 3 both indexes updated
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 3
+(1 row)
+
+DROP TABLE ex;
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This test is for a table with a custom type and a custom operators on
+-- the BTREE index. The question is, when comparing values for equality
+-- to determine if there are changes on the index or not... shouldn't we
+-- be using the custom operators?
+-- Create a type
+CREATE TYPE my_custom_type AS (val int);
+-- Comparison functions (returns boolean)
+CREATE FUNCTION my_custom_lt(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val < b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+CREATE FUNCTION my_custom_le(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val <= b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+CREATE FUNCTION my_custom_eq(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val = b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+CREATE FUNCTION my_custom_ge(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val >= b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+CREATE FUNCTION my_custom_gt(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val > b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+CREATE FUNCTION my_custom_ne(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val != b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+-- Comparison function (returns -1, 0, 1)
+CREATE FUNCTION my_custom_cmp(a my_custom_type, b my_custom_type) RETURNS int AS $$
+BEGIN
+ IF a.val < b.val THEN
+ RETURN -1;
+ ELSIF a.val > b.val THEN
+ RETURN 1;
+ ELSE
+ RETURN 0;
+ END IF;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+-- Create the operators
+CREATE OPERATOR < (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_lt,
+ COMMUTATOR = >,
+ NEGATOR = >=
+);
+CREATE OPERATOR <= (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_le,
+ COMMUTATOR = >=,
+ NEGATOR = >
+);
+CREATE OPERATOR = (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_eq,
+ COMMUTATOR = =,
+ NEGATOR = <>
+);
+CREATE OPERATOR >= (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_ge,
+ COMMUTATOR = <=,
+ NEGATOR = <
+);
+CREATE OPERATOR > (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_gt,
+ COMMUTATOR = <,
+ NEGATOR = <=
+);
+CREATE OPERATOR <> (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_ne,
+ COMMUTATOR = <>,
+ NEGATOR = =
+);
+-- Create the operator class (including the support function)
+CREATE OPERATOR CLASS my_custom_ops
+ DEFAULT FOR TYPE my_custom_type USING btree AS
+ OPERATOR 1 <,
+ OPERATOR 2 <=,
+ OPERATOR 3 =,
+ OPERATOR 4 >=,
+ OPERATOR 5 >,
+ FUNCTION 1 my_custom_cmp(my_custom_type, my_custom_type);
+-- Create the table
+CREATE TABLE my_table (
+ id int,
+ custom_val my_custom_type
+);
+-- Insert some data
+INSERT INTO my_table (id, custom_val) VALUES
+(1, ROW(3)::my_custom_type),
+(2, ROW(1)::my_custom_type),
+(3, ROW(4)::my_custom_type),
+(4, ROW(2)::my_custom_type);
+-- Create a function to use when indexing
+CREATE OR REPLACE FUNCTION abs_val(val my_custom_type) RETURNS int AS $$
+BEGIN
+ RETURN abs(val.val);
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+-- Create the index
+CREATE INDEX idx_custom_val_abs ON my_table (abs_val(custom_val));
+-- Update 1
+UPDATE my_table SET custom_val = ROW(5)::my_custom_type WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+-- Update 2
+UPDATE my_table SET custom_val = ROW(0)::my_custom_type WHERE custom_val < ROW(3)::my_custom_type;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+-- Update 3
+UPDATE my_table SET custom_val = ROW(6)::my_custom_type WHERE id = 3;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 0
+(1 row)
+
+-- Update 4
+UPDATE my_table SET id = 5 WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+ pg_stat_get_xact_tuples_hot_updated
+-------------------------------------
+ 1
+(1 row)
+
+-- Query using the index
+EXPLAIN (COSTS OFF) SELECT * FROM my_table WHERE abs_val(custom_val) = 6;
+ QUERY PLAN
+-------------------------------------
+ Seq Scan on my_table
+ Filter: (abs_val(custom_val) = 6)
+(2 rows)
+
+SELECT * FROM my_table WHERE abs_val(custom_val) = 6;
+ id | custom_val
+----+------------
+ 3 | (6)
+(1 row)
+
+-- Clean up
+DROP TABLE my_table CASCADE;
+DROP OPERATOR CLASS my_custom_ops USING btree CASCADE;
+DROP OPERATOR < (my_custom_type, my_custom_type);
+DROP OPERATOR <= (my_custom_type, my_custom_type);
+DROP OPERATOR = (my_custom_type, my_custom_type);
+DROP OPERATOR >= (my_custom_type, my_custom_type);
+DROP OPERATOR > (my_custom_type, my_custom_type);
+DROP OPERATOR <> (my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_lt(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_le(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_eq(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_ge(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_gt(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_ne(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_cmp(my_custom_type, my_custom_type);
+DROP FUNCTION abs_val(my_custom_type);
+DROP TYPE my_custom_type CASCADE;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index e63ee2cf2bb..f9def3d93aa 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -68,6 +68,11 @@ test: select_into select_distinct select_distinct_on select_implicit select_havi
# ----------
test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password identity generated_stored join_hash
+# ----------
+# Another group of parallel tests
+# ----------
+test: heap_hot_updates
+
# ----------
# Additional BRIN tests
# ----------
diff --git a/src/test/regress/sql/heap_hot_updates.sql b/src/test/regress/sql/heap_hot_updates.sql
new file mode 100644
index 00000000000..7728075a7ae
--- /dev/null
+++ b/src/test/regress/sql/heap_hot_updates.sql
@@ -0,0 +1,440 @@
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This table will have two columns and two indexes, one on the primary key
+-- id and one on the expression (info->>'name'). That means that the indexed
+-- attributes are 'id' and 'info'.
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name'));
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+
+-- Disable expression checks.
+ALTER TABLE keyvalue SET (expression_checks = false);
+SELECT reloptions FROM pg_class WHERE relname = 'keyvalue';
+
+-- While the indexed attribute "name" is unchanged we've disabled expression
+-- checks so this update should not go HOT as the system can't determine if
+-- the indexed attribute has changed without evaluating the expression.
+update keyvalue set info='{"name": "john", "data": "something else"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 0 row
+
+-- Re-enable expression checks.
+ALTER TABLE keyvalue SET (expression_checks = true);
+SELECT reloptions FROM pg_class WHERE relname = 'keyvalue';
+
+-- The indexed attribute "name" with value "john" is unchanged, expect a HOT update.
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 1 row
+
+-- The following update changes the indexed attribute "name", this should not be a HOT update.
+update keyvalue set info='{"name": "smith", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 1 no new HOT updates
+
+-- Now, this update does not change the indexed attribute "name" from "smith", this should be HOT.
+update keyvalue set info='{"name": "smith", "data": "some more data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 2 rows now
+drop table keyvalue;
+
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This table is the same as the previous one but it has a third index. The
+-- index 'colindex' isn't an expression index, it indexes the entire value
+-- in the info column. There are still only two indexed attributes for this
+-- relation, the same two as before. The presence of an index on the entire
+-- value of the info column should prevent HOT updates for any updates to any
+-- portion of JSONB content in that column.
+create table keyvalue(id integer primary key, info jsonb);
+create index nameindex on keyvalue((info->>'name'));
+create index colindex on keyvalue(info);
+insert into keyvalue values (1, '{"name": "john", "data": "some data"}');
+
+-- This update doesn't change the value of the expression index, but it does
+-- change the content of the info column and so should not be HOT because the
+-- indexed value changed as a result of the update.
+update keyvalue set info='{"name": "john", "data": "some other data"}' where id=1;
+select pg_stat_get_xact_tuples_hot_updated('keyvalue'::regclass); -- expect: 0 rows
+drop table keyvalue;
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- The table has one column docs and two indexes. They are both expression
+-- indexes referencing the same column attribute (docs) but one is a partial
+-- index.
+CREATE TABLE ex (docs JSONB) WITH (fillfactor = 60);
+INSERT INTO ex (docs) VALUES ('{"a": 0, "b": 0}');
+INSERT INTO ex (docs) SELECT jsonb_build_object('b', n) FROM generate_series(100, 10000) as n;
+CREATE INDEX idx_ex_a ON ex ((docs->>'a'));
+CREATE INDEX idx_ex_b ON ex ((docs->>'b')) WHERE (docs->>'b')::numeric > 9;
+
+-- We're using BTREE indexes and for this test we want to make sure that they remain
+-- in sync with changes to our relation. Force the choice of index scans below so
+-- that we know we're checking the index's understanding of what values should be
+-- in the index or not.
+SET SESSION enable_seqscan = OFF;
+SET SESSION enable_bitmapscan = OFF;
+
+-- Leave 'a' unchanged but modify 'b' to a value outside of the index predicate.
+-- This should be a HOT update because neither index is changed.
+UPDATE ex SET docs = jsonb_build_object('a', 0, 'b', 1) WHERE (docs->>'a')::numeric = 0;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 row
+-- Let's check to make sure that the index does not contain a value for 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+
+-- Leave 'a' unchanged but modify 'b' to a value within the index predicate.
+-- This represents a change for field 'b' from unindexed to indexed and so
+-- this should not take the HOT path.
+UPDATE ex SET docs = jsonb_build_object('a', 0, 'b', 10) WHERE (docs->>'a')::numeric = 0;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+-- Let's check to make sure that the index contains the new value of 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+
+-- This update modifies the value of 'a', an indexed field, so it also cannot
+-- be a HOT update.
+UPDATE ex SET docs = jsonb_build_object('a', 1, 'b', 10) WHERE (docs->>'b')::numeric = 10;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+
+-- This update changes both 'a' and 'b' to new values that require index updates,
+-- this cannot use the HOT path.
+UPDATE ex SET docs = jsonb_build_object('a', 2, 'b', 12) WHERE (docs->>'b')::numeric = 10;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+-- Let's check to make sure that the index contains the new value of 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+
+-- This update changes 'b' to a value outside its predicate requiring that
+-- we remove it from the index. That's a transition that can't be done
+-- during a HOT update.
+UPDATE ex SET docs = jsonb_build_object('a', 2, 'b', 1) WHERE (docs->>'b')::numeric = 12;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+-- Let's check to make sure that the index no longer contains the value of 'b'
+EXPLAIN (COSTS OFF) SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+SELECT * FROM ex WHERE (docs->>'b')::numeric > 9 AND (docs->>'b')::numeric < 100;
+
+-- Disable expression checks.
+ALTER TABLE ex SET (expression_checks = false);
+SELECT reloptions FROM pg_class WHERE relname = 'ex';
+
+-- This update changes 'b' to a value within its predicate just like it
+-- previous value, which would allow for a HOT update but with expression
+-- checks disabled we can't determine that so this should not be a HOT update.
+UPDATE ex SET docs = jsonb_build_object('a', 2, 'b', 2) WHERE (docs->>'b')::numeric = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 no new HOT updates
+
+
+-- Let's make sure we're recording HOT updates for our 'ex' relation properly in the system
+-- table pg_stat_user_tables. Note that statistics are stored within a transaction context
+-- first (xact) and then later into the global statistics for a relation, so first we need
+-- to ensure pending stats are flushed.
+SELECT pg_stat_force_next_flush();
+SELECT
+ c.relname AS table_name,
+ -- Transaction statistics
+ pg_stat_get_xact_tuples_updated(c.oid) AS xact_updates,
+ pg_stat_get_xact_tuples_hot_updated(c.oid) AS xact_hot_updates,
+ ROUND((
+ pg_stat_get_xact_tuples_hot_updated(c.oid)::float /
+ NULLIF(pg_stat_get_xact_tuples_updated(c.oid), 0) * 100
+ )::numeric, 2) AS xact_hot_update_percentage,
+ -- Cumulative statistics
+ s.n_tup_upd AS total_updates,
+ s.n_tup_hot_upd AS hot_updates,
+ ROUND((
+ s.n_tup_hot_upd::float /
+ NULLIF(s.n_tup_upd, 0) * 100
+ )::numeric, 2) AS total_hot_update_percentage
+FROM pg_class c
+LEFT JOIN pg_stat_user_tables s ON c.relname = s.relname
+WHERE c.relname = 'ex'
+AND c.relnamespace = 'public'::regnamespace;
+-- expect: 5 xact updates with 1 xact hot update and no cumulative updates as yet
+
+SET SESSION enable_seqscan = ON;
+SET SESSION enable_bitmapscan = ON;
+
+DROP TABLE ex;
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This table has a single column 'email' and a unique constraint on it that
+-- should preclude HOT updates.
+CREATE TABLE users (
+ user_id serial primary key,
+ name VARCHAR(255) NOT NULL,
+ email VARCHAR(255) NOT NULL,
+ EXCLUDE USING btree (lower(email) WITH =)
+);
+
+-- Add some data to the table and then update it in ways that should and should
+-- not be HOT updates.
+INSERT INTO users (name, email) VALUES
+('user1', '[email protected]'),
+('user2', '[email protected]'),
+('taken', '[email protected]'),
+('you', '[email protected]'),
+('taken', '[email protected]');
+
+-- Should fail because of the unique constraint on the email column.
+UPDATE users SET email = '[email protected]' WHERE email = '[email protected]';
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 0 no new HOT updates
+
+-- Should succeed because the email column is not being updated and should go HOT.
+UPDATE users SET name = 'foo' WHERE email = '[email protected]';
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 1 a single new HOT update
+
+-- Create a partial index on the email column, updates
+CREATE INDEX idx_users_email_no_example ON users (lower(email)) WHERE lower(email) LIKE '%@example.com%';
+
+-- An update that changes the email column but not the indexed portion of it and falls outside the constraint.
+-- Shouldn't be a HOT update because of the exclusion constraint.
+UPDATE users SET email = '[email protected]' WHERE name = 'you';
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 1 no new HOT updates
+
+-- An update that changes the email column but not the indexed portion of it and falls within the constraint.
+-- Again, should fail constraint and fail to be a HOT update.
+UPDATE users SET email = '[email protected]' WHERE name = 'you';
+SELECT pg_stat_get_xact_tuples_hot_updated('users'::regclass); -- expect: 1 no new HOT updates
+
+DROP TABLE users;
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- Another test of constraints spoiling HOT updates, this time with a range.
+CREATE TABLE events (
+ id serial primary key,
+ name VARCHAR(255) NOT NULL,
+ event_time tstzrange,
+ constraint no_screening_time_overlap exclude using gist (
+ event_time WITH &&
+ )
+);
+
+-- Add two non-overlapping events.
+INSERT INTO events (id, event_time, name)
+VALUES
+ (1, '["2023-01-01 19:00:00", "2023-01-01 20:45:00"]', 'event1'),
+ (2, '["2023-01-01 21:00:00", "2023-01-01 21:45:00"]', 'event2');
+
+-- Update the first event to overlap with the second, should fail the constraint and not be HOT.
+UPDATE events SET event_time = '["2023-01-01 20:00:00", "2023-01-01 21:45:00"]' WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('events'::regclass); -- expect: 0 no new HOT updates
+
+-- Update the first event to not overlap with the second, again not HOT due to the constraint.
+UPDATE events SET event_time = '["2023-01-01 22:00:00", "2023-01-01 22:45:00"]' WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('events'::regclass); -- expect: 0 no new HOT updates
+
+-- Update the first event to not overlap with the second, this time we're HOT because we don't overlap with the constraint.
+UPDATE events SET name = 'new name here' WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('events'::regclass); -- expect: 1 one new HOT update
+
+DROP TABLE events;
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- A test to ensure that summarizing indexes are not updated when they don't
+-- change, but are updated when they do while not prefent HOT updates.
+CREATE TABLE ex (att1 JSONB, att2 text) WITH (fillfactor = 60);
+CREATE INDEX expression ON ex USING btree((att1->'data'));
+CREATE INDEX summarizing ON ex USING BRIN(att2);
+INSERT INTO ex VALUES ('{"data": []}', 'nothing special');
+
+-- Update the unindexed value of att1, this should be a HOT update and not
+-- update the summarizing index.
+UPDATE ex SET att1 = att1 || '{"status": "checkmate"}';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 1 one new HOT update
+
+-- Update the indexed value of att2, a summarized value, this is a summarized
+-- only update and should use the HOT path while still triggering an update to
+-- the summarizing BRIN index.
+UPDATE ex SET att2 = 'special indeed';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 2 one new HOT update
+
+-- Update to att1 doesn't change the indexed value while the update to att2 does,
+-- this again is a summarized only update and should use the HOT path as well as
+-- trigger an update to the BRIN index.
+UPDATE ex SET att1 = att1 || '{"status": "checkmate!"}', att2 = 'special, so special';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 3 one new HOT update
+
+-- This updates both indexes, the expression index on att1 and the summarizing
+-- index on att2. This should not be a HOT update because there are modified
+-- indexes and only some are summarized, not all. This should force all
+-- indexes to be updated.
+UPDATE ex SET att1 = att1 || '{"data": [1,2,3]}', att2 = 'do you want to play a game?';
+SELECT pg_stat_get_xact_tuples_hot_updated('ex'::regclass); -- expect: 3 both indexes updated
+
+DROP TABLE ex;
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+-- This test is for a table with a custom type and a custom operators on
+-- the BTREE index. The question is, when comparing values for equality
+-- to determine if there are changes on the index or not... shouldn't we
+-- be using the custom operators?
+
+-- Create a type
+CREATE TYPE my_custom_type AS (val int);
+
+-- Comparison functions (returns boolean)
+CREATE FUNCTION my_custom_lt(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val < b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+CREATE FUNCTION my_custom_le(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val <= b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+CREATE FUNCTION my_custom_eq(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val = b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+CREATE FUNCTION my_custom_ge(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val >= b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+CREATE FUNCTION my_custom_gt(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val > b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+CREATE FUNCTION my_custom_ne(a my_custom_type, b my_custom_type) RETURNS boolean AS $$
+BEGIN
+ RETURN a.val != b.val;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+-- Comparison function (returns -1, 0, 1)
+CREATE FUNCTION my_custom_cmp(a my_custom_type, b my_custom_type) RETURNS int AS $$
+BEGIN
+ IF a.val < b.val THEN
+ RETURN -1;
+ ELSIF a.val > b.val THEN
+ RETURN 1;
+ ELSE
+ RETURN 0;
+ END IF;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+-- Create the operators
+CREATE OPERATOR < (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_lt,
+ COMMUTATOR = >,
+ NEGATOR = >=
+);
+
+CREATE OPERATOR <= (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_le,
+ COMMUTATOR = >=,
+ NEGATOR = >
+);
+
+CREATE OPERATOR = (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_eq,
+ COMMUTATOR = =,
+ NEGATOR = <>
+);
+
+CREATE OPERATOR >= (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_ge,
+ COMMUTATOR = <=,
+ NEGATOR = <
+);
+
+CREATE OPERATOR > (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_gt,
+ COMMUTATOR = <,
+ NEGATOR = <=
+);
+
+CREATE OPERATOR <> (
+ LEFTARG = my_custom_type,
+ RIGHTARG = my_custom_type,
+ PROCEDURE = my_custom_ne,
+ COMMUTATOR = <>,
+ NEGATOR = =
+);
+
+-- Create the operator class (including the support function)
+CREATE OPERATOR CLASS my_custom_ops
+ DEFAULT FOR TYPE my_custom_type USING btree AS
+ OPERATOR 1 <,
+ OPERATOR 2 <=,
+ OPERATOR 3 =,
+ OPERATOR 4 >=,
+ OPERATOR 5 >,
+ FUNCTION 1 my_custom_cmp(my_custom_type, my_custom_type);
+
+-- Create the table
+CREATE TABLE my_table (
+ id int,
+ custom_val my_custom_type
+);
+
+-- Insert some data
+INSERT INTO my_table (id, custom_val) VALUES
+(1, ROW(3)::my_custom_type),
+(2, ROW(1)::my_custom_type),
+(3, ROW(4)::my_custom_type),
+(4, ROW(2)::my_custom_type);
+
+-- Create a function to use when indexing
+CREATE OR REPLACE FUNCTION abs_val(val my_custom_type) RETURNS int AS $$
+BEGIN
+ RETURN abs(val.val);
+END;
+$$ LANGUAGE plpgsql IMMUTABLE STRICT;
+
+-- Create the index
+CREATE INDEX idx_custom_val_abs ON my_table (abs_val(custom_val));
+
+-- Update 1
+UPDATE my_table SET custom_val = ROW(5)::my_custom_type WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+
+-- Update 2
+UPDATE my_table SET custom_val = ROW(0)::my_custom_type WHERE custom_val < ROW(3)::my_custom_type;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+
+-- Update 3
+UPDATE my_table SET custom_val = ROW(6)::my_custom_type WHERE id = 3;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+
+-- Update 4
+UPDATE my_table SET id = 5 WHERE id = 1;
+SELECT pg_stat_get_xact_tuples_hot_updated('my_table'::regclass);
+
+-- Query using the index
+EXPLAIN (COSTS OFF) SELECT * FROM my_table WHERE abs_val(custom_val) = 6;
+SELECT * FROM my_table WHERE abs_val(custom_val) = 6;
+
+-- Clean up
+DROP TABLE my_table CASCADE;
+DROP OPERATOR CLASS my_custom_ops USING btree CASCADE;
+DROP OPERATOR < (my_custom_type, my_custom_type);
+DROP OPERATOR <= (my_custom_type, my_custom_type);
+DROP OPERATOR = (my_custom_type, my_custom_type);
+DROP OPERATOR >= (my_custom_type, my_custom_type);
+DROP OPERATOR > (my_custom_type, my_custom_type);
+DROP OPERATOR <> (my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_lt(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_le(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_eq(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_ge(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_gt(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_ne(my_custom_type, my_custom_type);
+DROP FUNCTION my_custom_cmp(my_custom_type, my_custom_type);
+DROP FUNCTION abs_val(my_custom_type);
+DROP TYPE my_custom_type CASCADE;
--
2.42.0
view thread (6+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected]
Subject: Re: Expanding HOT updates for expression and partial indexes
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox