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-rw-r--r--src/bin/pg_dump/pg_backup.h1
-rw-r--r--src/bin/pg_dump/pg_backup_archiver.c83
-rw-r--r--src/bin/pg_dump/pg_backup_archiver.h6
-rw-r--r--src/bin/pg_dump/pg_dump.c46
4 files changed, 120 insertions, 16 deletions
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index 658986de6f8..781f8fa1cc9 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -285,6 +285,7 @@ typedef int DumpId;
* Function pointer prototypes for assorted callback methods.
*/
+typedef char *(*DefnDumperPtr) (Archive *AH, const void *userArg);
typedef int (*DataDumperPtr) (Archive *AH, const void *userArg);
typedef void (*SetupWorkerPtrType) (Archive *AH);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 1d131e5a57d..2f902494e64 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -1266,6 +1266,9 @@ ArchiveEntry(Archive *AHX, CatalogId catalogId, DumpId dumpId,
newToc->dataDumperArg = opts->dumpArg;
newToc->hadDumper = opts->dumpFn ? true : false;
+ newToc->defnDumper = opts->defnFn;
+ newToc->defnDumperArg = opts->defnArg;
+
newToc->formatData = NULL;
newToc->dataLength = 0;
@@ -2621,7 +2624,45 @@ WriteToc(ArchiveHandle *AH)
WriteStr(AH, te->tag);
WriteStr(AH, te->desc);
WriteInt(AH, te->section);
- WriteStr(AH, te->defn);
+
+ if (te->defnLen)
+ {
+ /*
+ * defnLen should only be set for custom format's second call to
+ * WriteToc(), which rewrites the TOC in place to update data
+ * offsets. Instead of calling the defnDumper a second time
+ * (which could involve re-executing queries), just skip writing
+ * the entry. While regenerating the definition should
+ * theoretically produce the same result as before, it's expensive
+ * and feels risky.
+ *
+ * The custom format only calls WriteToc() a second time if
+ * fseeko() is usable (see _CloseArchive() in pg_backup_custom.c),
+ * so we can safely use it without checking. For other formats,
+ * we fail because one of our assumptions must no longer hold
+ * true.
+ *
+ * XXX This is a layering violation, but the alternative is an
+ * awkward and complicated callback infrastructure for this
+ * special case. This might be worth revisiting in the future.
+ */
+ if (AH->format != archCustom)
+ pg_fatal("unexpected TOC entry in WriteToc(): %d %s %s",
+ te->dumpId, te->desc, te->tag);
+
+ if (fseeko(AH->FH, te->defnLen, SEEK_CUR != 0))
+ pg_fatal("error during file seek: %m");
+ }
+ else if (te->defnDumper)
+ {
+ char *defn = te->defnDumper((Archive *) AH, te->defnDumperArg);
+
+ te->defnLen = WriteStr(AH, defn);
+ pg_free(defn);
+ }
+ else
+ WriteStr(AH, te->defn);
+
WriteStr(AH, te->dropStmt);
WriteStr(AH, te->copyStmt);
WriteStr(AH, te->namespace);
@@ -3849,7 +3890,7 @@ _printTocEntry(ArchiveHandle *AH, TocEntry *te, const char *pfx)
/*
* Actually print the definition. Normally we can just print the defn
- * string if any, but we have three special cases:
+ * string if any, but we have four special cases:
*
* 1. A crude hack for suppressing AUTHORIZATION clause that old pg_dump
* versions put into CREATE SCHEMA. Don't mutate the variant for schema
@@ -3862,6 +3903,11 @@ _printTocEntry(ArchiveHandle *AH, TocEntry *te, const char *pfx)
* 3. ACL LARGE OBJECTS entries need special processing because they
* contain only one copy of the ACL GRANT/REVOKE commands, which we must
* apply to each large object listed in the associated BLOB METADATA.
+ *
+ * 4. Entries with a defnDumper need to call it to generate the
+ * definition. This is primarily intended to provide a way to save memory
+ * for objects that would otherwise need a lot of it (e.g., statistics
+ * data).
*/
if (ropt->noOwner &&
strcmp(te->desc, "SCHEMA") == 0 && strncmp(te->defn, "--", 2) != 0)
@@ -3877,6 +3923,39 @@ _printTocEntry(ArchiveHandle *AH, TocEntry *te, const char *pfx)
{
IssueACLPerBlob(AH, te);
}
+ else if (te->defnLen && AH->format != archTar)
+ {
+ /*
+ * If defnLen is set, the defnDumper has already been called for this
+ * TOC entry. We don't normally expect a defnDumper to be called for
+ * a TOC entry a second time in _printTocEntry(), but there's an
+ * exception. The tar format first calls WriteToc(), which scans the
+ * entire TOC, and then it later calls RestoreArchive() to generate
+ * restore.sql, which scans the TOC again. There doesn't appear to be
+ * a good way to prevent a second defnDumper call in this case without
+ * storing the definition in memory, which defeats the purpose. This
+ * second defnDumper invocation should generate the same output as the
+ * first, but even if it doesn't, the worst-case scenario is that
+ * restore.sql might have different statistics data than the archive.
+ *
+ * In all other cases, encountering a TOC entry a second time in
+ * _printTocEntry() is unexpected, so we fail because one of our
+ * assumptions must no longer hold true.
+ *
+ * XXX This is a layering violation, but the alternative is an awkward
+ * and complicated callback infrastructure for this special case. This
+ * might be worth revisiting in the future.
+ */
+ pg_fatal("unexpected TOC entry in _printTocEntry(): %d %s %s",
+ te->dumpId, te->desc, te->tag);
+ }
+ else if (te->defnDumper)
+ {
+ char *defn = te->defnDumper((Archive *) AH, te->defnDumperArg);
+
+ te->defnLen = ahprintf(AH, "%s\n\n", defn);
+ pg_free(defn);
+ }
else if (te->defn && strlen(te->defn) > 0)
{
ahprintf(AH, "%s\n\n", te->defn);
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index a2064f471ed..b7ebc2b39cd 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -368,6 +368,10 @@ struct _tocEntry
const void *dataDumperArg; /* Arg for above routine */
void *formatData; /* TOC Entry data specific to file format */
+ DefnDumperPtr defnDumper; /* routine to dump definition statement */
+ const void *defnDumperArg; /* arg for above routine */
+ size_t defnLen; /* length of dumped definition */
+
/* working state while dumping/restoring */
pgoff_t dataLength; /* item's data size; 0 if none or unknown */
int reqs; /* do we need schema and/or data of object
@@ -407,6 +411,8 @@ typedef struct _archiveOpts
int nDeps;
DataDumperPtr dumpFn;
const void *dumpArg;
+ DefnDumperPtr defnFn;
+ const void *defnArg;
} ArchiveOpts;
#define ARCHIVE_OPTS(...) &(ArchiveOpts){__VA_ARGS__}
/* Called to add a TOC entry */
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 9436b25290d..e553cc84934 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -10554,17 +10554,21 @@ appendNamedArgument(PQExpBuffer out, Archive *fout, const char *argname,
}
/*
- * dumpRelationStats --
+ * dumpRelationStats_dumper --
*
- * Dump command to import stats into the relation on the new database.
+ * Generate command to import stats into the relation on the new database.
+ * This routine is called by the Archiver when it wants the statistics to be
+ * dumped.
*/
-static void
-dumpRelationStats(Archive *fout, const RelStatsInfo *rsinfo)
+static char *
+dumpRelationStats_dumper(Archive *fout, const void *userArg)
{
+ const RelStatsInfo *rsinfo = (RelStatsInfo *) userArg;
const DumpableObject *dobj = &rsinfo->dobj;
PGresult *res;
PQExpBuffer query;
- PQExpBuffer out;
+ PQExpBufferData out_data;
+ PQExpBuffer out = &out_data;
int i_attname;
int i_inherited;
int i_null_frac;
@@ -10581,10 +10585,6 @@ dumpRelationStats(Archive *fout, const RelStatsInfo *rsinfo)
int i_range_empty_frac;
int i_range_bounds_histogram;
- /* nothing to do if we are not dumping statistics */
- if (!fout->dopt->dumpStatistics)
- return;
-
query = createPQExpBuffer();
if (!fout->is_prepared[PREPQUERY_GETATTRIBUTESTATS])
{
@@ -10620,7 +10620,7 @@ dumpRelationStats(Archive *fout, const RelStatsInfo *rsinfo)
resetPQExpBuffer(query);
}
- out = createPQExpBuffer();
+ initPQExpBuffer(out);
/* restore relation stats */
appendPQExpBufferStr(out, "SELECT * FROM pg_catalog.pg_restore_relation_stats(\n");
@@ -10764,17 +10764,35 @@ dumpRelationStats(Archive *fout, const RelStatsInfo *rsinfo)
PQclear(res);
+ destroyPQExpBuffer(query);
+ return out->data;
+}
+
+/*
+ * dumpRelationStats --
+ *
+ * Make an ArchiveEntry for the relation statistics. The Archiver will take
+ * care of gathering the statistics and generating the restore commands when
+ * they are needed.
+ */
+static void
+dumpRelationStats(Archive *fout, const RelStatsInfo *rsinfo)
+{
+ const DumpableObject *dobj = &rsinfo->dobj;
+
+ /* nothing to do if we are not dumping statistics */
+ if (!fout->dopt->dumpStatistics)
+ return;
+
ArchiveEntry(fout, nilCatalogId, createDumpId(),
ARCHIVE_OPTS(.tag = dobj->name,
.namespace = dobj->namespace->dobj.name,
.description = "STATISTICS DATA",
.section = rsinfo->section,
- .createStmt = out->data,
+ .defnFn = dumpRelationStats_dumper,
+ .defnArg = rsinfo,
.deps = dobj->dependencies,
.nDeps = dobj->nDeps));
-
- destroyPQExpBuffer(out);
- destroyPQExpBuffer(query);
}
/*
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-25 21:50:43 +0000