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[PATCH 7/8] add wal_compression_method=zstd 2+ messages / 2 participants [nested] [flat]
* [PATCH 7/8] add wal_compression_method=zstd @ 2021-03-12 20:43 Justin Pryzby <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Justin Pryzby @ 2021-03-12 20:43 UTC (permalink / raw) --- configure | 163 ++++++++++++++++++++++++ configure.ac | 26 ++++ src/backend/access/transam/xlog.c | 3 + src/backend/access/transam/xloginsert.c | 20 +++ src/backend/access/transam/xlogreader.c | 15 +++ src/include/access/xlog_internal.h | 1 + src/include/pg_config.h.in | 3 + src/tools/msvc/Solution.pm | 1 + 8 files changed, 232 insertions(+) diff --git a/configure b/configure index 3afa1e87e3..c7c4c951a7 100755 --- a/configure +++ b/configure @@ -699,6 +699,9 @@ with_gnu_ld LD LDFLAGS_SL LDFLAGS_EX +ZSTD_LIBS +ZSTD_CFLAGS +with_zstd LZ4_LIBS LZ4_CFLAGS with_lz4 @@ -868,6 +871,7 @@ with_libxslt with_system_tzdata with_zlib with_lz4 +with_zstd with_gnu_ld with_ssl with_openssl @@ -897,6 +901,8 @@ XML2_CFLAGS XML2_LIBS LZ4_CFLAGS LZ4_LIBS +ZSTD_CFLAGS +ZSTD_LIBS LDFLAGS_EX LDFLAGS_SL PERL @@ -1576,6 +1582,7 @@ Optional Packages: use system time zone data in DIR --without-zlib do not use Zlib --without-lz4 build without LZ4 support + --with-zstd build with zstd support --with-gnu-ld assume the C compiler uses GNU ld [default=no] --with-ssl=LIB use LIB for SSL/TLS support (openssl) --with-openssl obsolete spelling of --with-ssl=openssl @@ -1605,6 +1612,8 @@ Some influential environment variables: XML2_LIBS linker flags for XML2, overriding pkg-config LZ4_CFLAGS C compiler flags for LZ4, overriding pkg-config LZ4_LIBS linker flags for LZ4, overriding pkg-config + ZSTD_CFLAGS C compiler flags for ZSTD, overriding pkg-config + ZSTD_LIBS linker flags for ZSTD, overriding pkg-config LDFLAGS_EX extra linker flags for linking executables only LDFLAGS_SL extra linker flags for linking shared libraries only PERL Perl program @@ -8705,6 +8714,137 @@ fi CFLAGS="$LZ4_CFLAGS $CFLAGS" fi +# +# ZSTD +# +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build with zstd support" >&5 +$as_echo_n "checking whether to build with zstd support... " >&6; } + + + +# Check whether --with-zstd was given. +if test "${with_zstd+set}" = set; then : + withval=$with_zstd; + case $withval in + yes) + +$as_echo "#define USE_ZSTD 1" >>confdefs.h + + ;; + no) + : + ;; + *) + as_fn_error $? "no argument expected for --with-zstd option" "$LINENO" 5 + ;; + esac + +else + with_zstd=no + +fi + + +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $with_zstd" >&5 +$as_echo "$with_zstd" >&6; } + + +if test "$with_zstd" = yes; then + +pkg_failed=no +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for libzstd" >&5 +$as_echo_n "checking for libzstd... " >&6; } + +if test -n "$ZSTD_CFLAGS"; then + pkg_cv_ZSTD_CFLAGS="$ZSTD_CFLAGS" + elif test -n "$PKG_CONFIG"; then + if test -n "$PKG_CONFIG" && \ + { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libzstd\""; } >&5 + ($PKG_CONFIG --exists --print-errors "libzstd") 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; then + pkg_cv_ZSTD_CFLAGS=`$PKG_CONFIG --cflags "libzstd" 2>/dev/null` + test "x$?" != "x0" && pkg_failed=yes +else + pkg_failed=yes +fi + else + pkg_failed=untried +fi +if test -n "$ZSTD_LIBS"; then + pkg_cv_ZSTD_LIBS="$ZSTD_LIBS" + elif test -n "$PKG_CONFIG"; then + if test -n "$PKG_CONFIG" && \ + { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libzstd\""; } >&5 + ($PKG_CONFIG --exists --print-errors "libzstd") 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; then + pkg_cv_ZSTD_LIBS=`$PKG_CONFIG --libs "libzstd" 2>/dev/null` + test "x$?" != "x0" && pkg_failed=yes +else + pkg_failed=yes +fi + else + pkg_failed=untried +fi + + + +if test $pkg_failed = yes; then + { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5 +$as_echo "no" >&6; } + +if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then + _pkg_short_errors_supported=yes +else + _pkg_short_errors_supported=no +fi + if test $_pkg_short_errors_supported = yes; then + ZSTD_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "libzstd" 2>&1` + else + ZSTD_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "libzstd" 2>&1` + fi + # Put the nasty error message in config.log where it belongs + echo "$ZSTD_PKG_ERRORS" >&5 + + as_fn_error $? "Package requirements (libzstd) were not met: + +$ZSTD_PKG_ERRORS + +Consider adjusting the PKG_CONFIG_PATH environment variable if you +installed software in a non-standard prefix. + +Alternatively, you may set the environment variables ZSTD_CFLAGS +and ZSTD_LIBS to avoid the need to call pkg-config. +See the pkg-config man page for more details." "$LINENO" 5 +elif test $pkg_failed = untried; then + { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5 +$as_echo "no" >&6; } + { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5 +$as_echo "$as_me: error: in \`$ac_pwd':" >&2;} +as_fn_error $? "The pkg-config script could not be found or is too old. Make sure it +is in your PATH or set the PKG_CONFIG environment variable to the full +path to pkg-config. + +Alternatively, you may set the environment variables ZSTD_CFLAGS +and ZSTD_LIBS to avoid the need to call pkg-config. +See the pkg-config man page for more details. + +To get pkg-config, see <http://pkg-config.freedesktop.org/;. +See \`config.log' for more details" "$LINENO" 5; } +else + ZSTD_CFLAGS=$pkg_cv_ZSTD_CFLAGS + ZSTD_LIBS=$pkg_cv_ZSTD_LIBS + { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5 +$as_echo "yes" >&6; } + +fi + LIBS="$ZSTD_LIBS $LIBS" + CFLAGS="$ZSTD_CFLAGS $CFLAGS" +fi + # # Assignments # @@ -13556,6 +13696,29 @@ done CPPFLAGS=$ac_save_CPPFLAGS fi +if test "$with_zstd" = yes; then + ac_save_CPPFLAGS=$CPPFLAGS + CPPFLAGS="$ZSTD_CFLAGS $CPPFLAGS" + + # Verify we have zstd's header files + for ac_header in zstd.h +do : + ac_fn_c_check_header_mongrel "$LINENO" "zstd.h" "ac_cv_header_zstd_h" "$ac_includes_default" +if test "x$ac_cv_header_zstd_h" = xyes; then : + cat >>confdefs.h <<_ACEOF +#define HAVE_ZSTD_H 1 +_ACEOF + +else + as_fn_error $? "zstd.h header file is required for zstd" "$LINENO" 5 +fi + +done + + + CPPFLAGS=$ac_save_CPPFLAGS +fi + if test "$with_gssapi" = yes ; then for ac_header in gssapi/gssapi.h do : diff --git a/configure.ac b/configure.ac index d62ea5f742..abac4b28f6 100644 --- a/configure.ac +++ b/configure.ac @@ -1001,6 +1001,21 @@ if test "$with_lz4" = yes; then CFLAGS="$LZ4_CFLAGS $CFLAGS" fi +# +# ZSTD +# +AC_MSG_CHECKING([whether to build with zstd support]) +PGAC_ARG_BOOL(with, zstd, no, [build with zstd support], + [AC_DEFINE([USE_ZSTD], 1, [Define to 1 to build with zstd support. (--with-zstd)])]) +AC_MSG_RESULT([$with_zstd]) +AC_SUBST(with_zstd) + +if test "$with_zstd" = yes; then + PKG_CHECK_MODULES(ZSTD, libzstd) + LIBS="$ZSTD_LIBS $LIBS" + CFLAGS="$ZSTD_CFLAGS $CFLAGS" +fi + # # Assignments # @@ -1433,6 +1448,17 @@ if test "$with_lz4" = yes; then CPPFLAGS=$ac_save_CPPFLAGS fi +if test "$with_zstd" = yes; then + ac_save_CPPFLAGS=$CPPFLAGS + CPPFLAGS="$ZSTD_CFLAGS $CPPFLAGS" + + # Verify we have zstd's header files + AC_CHECK_HEADERS(zstd.h, [], + [AC_MSG_ERROR([zstd.h header file is required for zstd])]) + + CPPFLAGS=$ac_save_CPPFLAGS +fi + if test "$with_gssapi" = yes ; then AC_CHECK_HEADERS(gssapi/gssapi.h, [], [AC_CHECK_HEADERS(gssapi.h, [], [AC_MSG_ERROR([gssapi.h header file is required for GSSAPI])])]) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index f33355e44a..f2749ebf45 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -189,6 +189,9 @@ const struct config_enum_entry wal_compression_options[] = { #endif #ifdef USE_LZ4 {"lz4", WAL_COMPRESSION_LZ4, false}, +#endif +#ifdef USE_ZSTD + {"zstd", WAL_COMPRESSION_ZSTD, false}, #endif {NULL, 0, false} }; diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c index 38ac5f9e94..852e5ef7af 100644 --- a/src/backend/access/transam/xloginsert.c +++ b/src/backend/access/transam/xloginsert.c @@ -41,6 +41,10 @@ #include "lz4.h" #endif +#ifdef USE_ZSTD +#include "zstd.h" +#endif + /* Buffer size required to store a compressed version of backup block image */ #define PGLZ_MAX_BLCKSZ PGLZ_MAX_OUTPUT(BLCKSZ) @@ -896,6 +900,22 @@ XLogCompressBackupBlock(char *page, uint16 hole_offset, uint16 hole_length, break; #endif +#ifdef USE_ZSTD + case WAL_COMPRESSION_ZSTD: + len = ZSTD_compress(dest, PGLZ_MAX_BLCKSZ, + source, orig_len, ZSTD_CLEVEL_DEFAULT); + if (ZSTD_isError(len)) + { + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("failed compressing zstd: %s", + ZSTD_getErrorName(len)))); + len = -1; + } + + break; +#endif + default: /* * It should be impossible to get here for unsupported algorithms, diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c index 920c47e4d7..6ce2fbfb13 100644 --- a/src/backend/access/transam/xlogreader.c +++ b/src/backend/access/transam/xlogreader.c @@ -41,6 +41,10 @@ #include "lz4.h" #endif +#ifdef USE_ZSTD +#include "zstd.h" +#endif + static void report_invalid_record(XLogReaderState *state, const char *fmt,...) pg_attribute_printf(2, 3); static bool allocate_recordbuf(XLogReaderState *state, uint32 reclength); @@ -1564,6 +1568,8 @@ wal_compression_name(WalCompression compression) return "zlib"; case WAL_COMPRESSION_LZ4: return "lz4"; + case WAL_COMPRESSION_ZSTD: + return "zstd"; default: return "???"; } @@ -1619,6 +1625,15 @@ RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page) break; #endif +#ifdef USE_ZSTD + case WAL_COMPRESSION_ZSTD: + decomp_result = ZSTD_decompress(tmp.data, BLCKSZ, ptr, bkpb->bimg_len); + // XXX: ZSTD_getErrorName + if (ZSTD_isError(decomp_result)) + decomp_result = -1; + break; +#endif + default: report_invalid_record(record, "image at %X/%X is compressed with unsupported codec, block %d (%d/%s)", (uint32) (record->ReadRecPtr >> 32), diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h index 0993de784e..30f663f448 100644 --- a/src/include/access/xlog_internal.h +++ b/src/include/access/xlog_internal.h @@ -329,6 +329,7 @@ typedef enum WalCompression WAL_COMPRESSION_PGLZ = 0, WAL_COMPRESSION_ZLIB = 1, WAL_COMPRESSION_LZ4 = 2, + WAL_COMPRESSION_ZSTD = 3, } WalCompression; extern const char *wal_compression_name(WalCompression compression); diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index 0a6422da4f..ad26393352 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -902,6 +902,9 @@ /* Define to 1 to build with LZ4 support (--with-lz4) */ #undef USE_LZ4 +/* Define to 1 if you have the `zstd' library (-lzstd). */ +#undef USE_ZSTD + /* Define to select named POSIX semaphores. */ #undef USE_NAMED_POSIX_SEMAPHORES diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm index 14605371bb..7dfa0f31f6 100644 --- a/src/tools/msvc/Solution.pm +++ b/src/tools/msvc/Solution.pm @@ -307,6 +307,7 @@ sub GenerateFiles HAVE_LIBXML2 => undef, HAVE_LIBXSLT => undef, HAVE_LIBZ => $self->{options}->{zlib} ? 1 : undef, + HAVE_LIBZSTD => $self->{options}->{zstd} ? 1 : undef, HAVE_LINK => undef, HAVE_LOCALE_T => 1, HAVE_LONG_INT_64 => undef, -- 2.17.0 --f0KYrhQ4vYSV2aJu-- ^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: Hash-based MCV matching for large IN-lists @ 2026-01-05 08:54 David Geier <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: David Geier @ 2026-01-05 08:54 UTC (permalink / raw) To: Ilia Evdokimov <[email protected]>; PostgreSQL Hackers <[email protected]> Hi Ilia! On 29.12.2025 21:35, Ilia Evdokimov wrote: > Hi hackers, > > When estimating selectivity for ScalarArrayOpExpr (IN, ANY, ALL) and MCV > statistics are available for the column, the planner currently matches > IN-list elements against the MCV array using nested loop. For large IN- > list and large MCV arrays this results in O(N*M) behavior, which can > become unnecessarily expensive during planning. > > Thanks to David for pointing out this case [0] > Cool that you tackled this. I've seen this happening a lot in practice. > This patch introduces a hash-based matching path, analogous to what is > already done for MCV matching in join selectivity estimation (057012b > commit). Instead of linearly scanning the MCV array for each IN-list > element, we build a hash table and probe it to identify matches. > > The hash table is built over the MCV values, not over the IN-list. The > IN-list may contain NULLs, non-Const expressions, and duplicate values, > whereas the MCV list is guaranteed to contain distinct, non-NULL values > and represents the statistically meaningful domain we are matching > against. Hashing the MCVs therefore avoids duplicate work and directly > supports selectivity estimation. The downside of doing it this way is that we always pay the price of building a possibly big hash table if the column has a lot of MCVs, even for small IN lists. Why can't we build the hash table always on the smaller list, like we do already in the join selectivity estimation? For NULL we can add a flag to the hash entry, non-Const expressions must anyways be evaluated and duplicate values will be discarded during insert. > > For each IN-list element, if a matching MCV is found, we add the > corresponding MCV frequency to the selectivity estimate. If no match is > found, the remaining selectivity is estimated in the same way as the > existing non-MCV path (similar to var_eq_const when the constant is not > present in the MCV list). > The code in master currently calls an operator-specific selectivity estimation function. For equality this is typically eqsel() but the function can be specified during CREATE OPERATOR. Can be safely special-case the behavior of eqsel() for all possible operators for the ScalarArrayOpExpr case? > The hash-based path is enabled only when both a sufficiently large IN- > list and an MCV list are present, and suitable hash functions exist for > the equality operator. The threshold is currently the same as the one > used for join MCV hashing, since the underlying algorithmic tradeoffs > are similar. Seems reasonable. I'll test and review in more detail once we clarified the design. -- David Geier ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2026-01-05 08:54 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2021-03-12 20:43 [PATCH 7/8] add wal_compression_method=zstd Justin Pryzby <[email protected]> 2026-01-05 08:54 Re: Hash-based MCV matching for large IN-lists David Geier <[email protected]>
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