Hi hackers, Commit 6d0eba66275 already did most of the changes but missed the opportunities to $SUBJECT in sequencesync.c.
Indeed, 5509055d6956 added a few cases that are using StringInfo but don't need that StringInfo to exist beyond the scope of the function were using makeStringInfo(), which allocates both a StringInfoData and the buffer it uses as two separate allocations. It's more efficient for these cases to use a StringInfoData on the stack and initialize it with initStringInfo(), which only allocates the string buffer. The reason 6d0eba66275 missed those is that 5509055d6956 has been committed between the patch proposal for 6d0eba66275 and 6d0eba66275. I used Mats's coccinelle script (mentioned in [1]) to find those and they are the only remaining ones. [1]: https://postgr.es/m/4379aac8-26f1-42f2-a356-ff0e886228d3%40gmail.com Regards, -- Bertrand Drouvot PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
>From e9d28b00e920c5f7ecc1bd9a3041a0c922da1b43 Mon Sep 17 00:00:00 2001 From: Bertrand Drouvot <[email protected]> Date: Sun, 12 Apr 2026 10:09:22 +0000 Subject: [PATCH v1] Use stack allocated StringInfoDatas, where possible Commit 6d0eba66275 already did most of the changes but missed the opportunities in sequencesync.c. Indeed, 5509055d6956 added a few cases that are using StringInfo but don't need that StringInfo to exist beyond the scope of the function were using makeStringInfo(), which allocates both a StringInfoData and the buffer it uses as two separate allocations. It's more efficient for these cases to use a StringInfoData on the stack and initialize it with initStringInfo(), which only allocates the string buffer. The reason 6d0eba66275 missed those is that 5509055d6956 has been committed between the patch proposal for 6d0eba66275 and 6d0eba66275. Author: Bertrand Drouvot <[email protected]> --- .../replication/logical/sequencesync.c | 39 ++++++++++--------- 1 file changed, 21 insertions(+), 18 deletions(-) 100.0% src/backend/replication/logical/ diff --git a/src/backend/replication/logical/sequencesync.c b/src/backend/replication/logical/sequencesync.c index a4fb6783ba9..ec7e76abf93 100644 --- a/src/backend/replication/logical/sequencesync.c +++ b/src/backend/replication/logical/sequencesync.c @@ -174,45 +174,45 @@ static void report_sequence_errors(List *mismatched_seqs_idx, List *insuffperm_seqs_idx, List *missing_seqs_idx) { - StringInfo seqstr; + StringInfoData seqstr; /* Quick exit if there are no errors to report */ if (!mismatched_seqs_idx && !insuffperm_seqs_idx && !missing_seqs_idx) return; - seqstr = makeStringInfo(); + initStringInfo(&seqstr); if (mismatched_seqs_idx) { - get_sequences_string(mismatched_seqs_idx, seqstr); + get_sequences_string(mismatched_seqs_idx, &seqstr); ereport(WARNING, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg_plural("mismatched or renamed sequence on subscriber (%s)", "mismatched or renamed sequences on subscriber (%s)", list_length(mismatched_seqs_idx), - seqstr->data)); + seqstr.data)); } if (insuffperm_seqs_idx) { - get_sequences_string(insuffperm_seqs_idx, seqstr); + get_sequences_string(insuffperm_seqs_idx, &seqstr); ereport(WARNING, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg_plural("insufficient privileges on sequence (%s)", "insufficient privileges on sequences (%s)", list_length(insuffperm_seqs_idx), - seqstr->data)); + seqstr.data)); } if (missing_seqs_idx) { - get_sequences_string(missing_seqs_idx, seqstr); + get_sequences_string(missing_seqs_idx, &seqstr); ereport(WARNING, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg_plural("missing sequence on publisher (%s)", "missing sequences on publisher (%s)", list_length(missing_seqs_idx), - seqstr->data)); + seqstr.data)); } ereport(ERROR, @@ -388,10 +388,13 @@ copy_sequences(WalReceiverConn *conn) List *mismatched_seqs_idx = NIL; List *missing_seqs_idx = NIL; List *insuffperm_seqs_idx = NIL; - StringInfo seqstr = makeStringInfo(); - StringInfo cmd = makeStringInfo(); + StringInfoData seqstr; + StringInfoData cmd; MemoryContext oldctx; + initStringInfo(&seqstr); + initStringInfo(&cmd); + #define MAX_SEQUENCES_SYNC_PER_BATCH 100 elog(DEBUG1, @@ -423,13 +426,13 @@ copy_sequences(WalReceiverConn *conn) LogicalRepSequenceInfo *seqinfo = (LogicalRepSequenceInfo *) list_nth(seqinfos, idx); - if (seqstr->len > 0) - appendStringInfoString(seqstr, ", "); + if (seqstr.len > 0) + appendStringInfoString(&seqstr, ", "); nspname_literal = quote_literal_cstr(seqinfo->nspname); seqname_literal = quote_literal_cstr(seqinfo->seqname); - appendStringInfo(seqstr, "(%s, %s, %d)", + appendStringInfo(&seqstr, "(%s, %s, %d)", nspname_literal, seqname_literal, idx); if (++batch_size == MAX_SEQUENCES_SYNC_PER_BATCH) @@ -468,7 +471,7 @@ copy_sequences(WalReceiverConn *conn) * corresponding local entries without relying on result order or name * matching. */ - appendStringInfo(cmd, + appendStringInfo(&cmd, "SELECT s.seqidx, ps.*, seq.seqtypid,\n" " seq.seqstart, seq.seqincrement, seq.seqmin,\n" " seq.seqmax, seq.seqcycle\n" @@ -477,9 +480,9 @@ copy_sequences(WalReceiverConn *conn) "JOIN pg_class c ON c.relnamespace = n.oid AND c.relname = s.seqname\n" "JOIN pg_sequence seq ON seq.seqrelid = c.oid\n" "JOIN LATERAL pg_get_sequence_data(seq.seqrelid) AS ps ON true\n", - seqstr->data); + seqstr.data); - res = walrcv_exec(conn, cmd->data, lengthof(seqRow), seqRow); + res = walrcv_exec(conn, cmd.data, lengthof(seqRow), seqRow); if (res->status != WALRCV_OK_TUPLES) ereport(ERROR, errcode(ERRCODE_CONNECTION_FAILURE), @@ -567,8 +570,8 @@ copy_sequences(WalReceiverConn *conn) ExecDropSingleTupleTableSlot(slot); walrcv_clear_result(res); - resetStringInfo(seqstr); - resetStringInfo(cmd); + resetStringInfo(&seqstr); + resetStringInfo(&cmd); batch_missing_count = batch_size - (batch_succeeded_count + batch_mismatched_count + -- 2.34.1
