From b590247938434d4f0fa2360069ad797fd30b7181 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Tue, 30 Apr 2024 19:33:24 -0500
Subject: [PATCH v1 3/3] cache more sequence data

---
 src/bin/pg_dump/pg_dump.c | 72 +++++++++++++++++++++++++++++----------
 1 file changed, 54 insertions(+), 18 deletions(-)

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 98cc2698ac..02bf4f65e6 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -103,6 +103,8 @@ typedef struct
 	int64		startv;
 	int64		incby;
 	int64		cache;
+	int64		last_value;
+	bool		is_called;
 } SequenceItem;
 
 typedef enum OidOptions
@@ -17602,11 +17604,24 @@ collectSequences(Archive *fout)
 	PGresult   *res;
 	const char *query;
 
+	if (fout->remoteVersion < 100000)
+		return;
+
 	query = "SELECT seqrelid, format_type(seqtypid, NULL), "
 		"seqstart, seqincrement, "
 		"seqmax, seqmin, "
-		"seqcache, seqcycle "
-		"FROM pg_catalog.pg_sequence "
+		"seqcache, seqcycle, "
+		"CASE WHEN has_sequence_privilege(seqrelid, 'SELECT,USAGE'::text) "
+		"AND (pg_is_in_recovery() = 'f' OR c.relpersistence = 'p') "
+		"THEN pg_sequence_last_value(seqrelid) IS NOT NULL "
+		"ELSE 'f' END AS is_called, "
+		"CASE WHEN has_sequence_privilege(seqrelid, 'SELECT,USAGE'::text) "
+		"AND (pg_is_in_recovery() = 'f' OR c.relpersistence = 'p') "
+		"AND pg_sequence_last_value(seqrelid) IS NOT NULL "
+		"THEN pg_sequence_last_value(seqrelid) "
+		"ELSE seqstart END AS last_value "
+		"FROM pg_catalog.pg_sequence s "
+		"JOIN pg_class c ON s.seqrelid = c.oid "
 		"ORDER BY seqrelid";
 
 	res = ExecuteSqlQuery(fout, query, PGRES_TUPLES_OK);
@@ -17630,6 +17645,8 @@ collectSequences(Archive *fout)
 		sequences[i].minv = strtoi64(PQgetvalue(res, i, 5), NULL, 10);
 		sequences[i].cache = strtoi64(PQgetvalue(res, i, 6), NULL, 10);
 		sequences[i].cycled = (strcmp(PQgetvalue(res, i, 7), "t") == 0);
+		sequences[i].is_called = (strcmp(PQgetvalue(res, i, 8), "t") == 0);
+		sequences[i].last_value = strtoi64(PQgetvalue(res, i, 9), NULL, 10);
 	}
 
 	PQclear(res);
@@ -17906,30 +17923,51 @@ static void
 dumpSequenceData(Archive *fout, const TableDataInfo *tdinfo)
 {
 	TableInfo  *tbinfo = tdinfo->tdtable;
-	PGresult   *res;
-	char	   *last;
+	int64		last;
 	bool		called;
 	PQExpBuffer query = createPQExpBuffer();
 
-	appendPQExpBuffer(query,
-					  "SELECT last_value, is_called FROM %s",
-					  fmtQualifiedDumpable(tbinfo));
+	if (fout->remoteVersion < 100000)
+	{
+		PGresult   *res;
 
-	res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+		appendPQExpBuffer(query,
+						  "SELECT last_value, is_called FROM %s",
+						  fmtQualifiedDumpable(tbinfo));
 
-	if (PQntuples(res) != 1)
-		pg_fatal(ngettext("query to get data of sequence \"%s\" returned %d row (expected 1)",
-						  "query to get data of sequence \"%s\" returned %d rows (expected 1)",
-						  PQntuples(res)),
-				 tbinfo->dobj.name, PQntuples(res));
+		res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
 
-	last = PQgetvalue(res, 0, 0);
-	called = (strcmp(PQgetvalue(res, 0, 1), "t") == 0);
+		if (PQntuples(res) != 1)
+			pg_fatal(ngettext("query to get data of sequence \"%s\" returned %d row (expected 1)",
+							  "query to get data of sequence \"%s\" returned %d rows (expected 1)",
+							  PQntuples(res)),
+					 tbinfo->dobj.name, PQntuples(res));
+
+		last = strtoi64(PQgetvalue(res, 0, 0), NULL, 10);
+		called = (strcmp(PQgetvalue(res, 0, 1), "t") == 0);
+
+		PQclear(res);
+	}
+	else
+	{
+		SequenceItem key = {0};
+		SequenceItem *entry;
+
+		Assert(sequences);
+		Assert(tbinfo->dobj.catId.oid);
+
+		key.oid = tbinfo->dobj.catId.oid;
+		entry = bsearch(&key, sequences, nsequences,
+						sizeof(SequenceItem), SequenceItemCmp);
+
+		last = entry->last_value;
+		called = entry->is_called;
+	}
 
 	resetPQExpBuffer(query);
 	appendPQExpBufferStr(query, "SELECT pg_catalog.setval(");
 	appendStringLiteralAH(query, fmtQualifiedDumpable(tbinfo), fout);
-	appendPQExpBuffer(query, ", %s, %s);\n",
+	appendPQExpBuffer(query, ", " INT64_FORMAT ", %s);\n",
 					  last, (called ? "true" : "false"));
 
 	if (tdinfo->dobj.dump & DUMP_COMPONENT_DATA)
@@ -17943,8 +17981,6 @@ dumpSequenceData(Archive *fout, const TableDataInfo *tdinfo)
 								  .deps = &(tbinfo->dobj.dumpId),
 								  .nDeps = 1));
 
-	PQclear(res);
-
 	destroyPQExpBuffer(query);
 }
 
-- 
2.25.1