From 54bb91c30e3964fd81059e6b02e377cc9dd2d64c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 30 Mar 2021 10:57:57 -0400 Subject: [PATCH] Further tweaking of pg_dump's handling of default_toast_compression. As committed in bbe0a81db, pg_dump from a pre-v14 server effectively acts as though you'd said --no-toast-compression. I think the right thing is for it to act as though default_toast_compression is set to "pglz", instead, so that the tables' toast compression behavior is preserved. You can always get the other behavior, if you want that, by giving the switch. Discussion: https://postgr.es/m/1112852.1616609702@sss.pgh.pa.us --- src/bin/pg_dump/pg_dump.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index da6cc054b08..b72adcfbb8d 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -3333,18 +3333,28 @@ dumpSearchPath(Archive *AH) static void dumpToastCompression(Archive *AH) { - const char *toast_compression; + char *toast_compression; PQExpBuffer qry; - PGresult *res; - if (AH->remoteVersion < 140000 || AH->dopt->no_toast_compression) + if (AH->dopt->no_toast_compression) { - /* server doesn't support compression, or we don't care */ + /* we don't intend to dump the info, so no need to fetch it either */ return; } - res = ExecuteSqlQueryForSingleRow(AH, "SHOW default_toast_compression"); - toast_compression = PQgetvalue(res, 0, 0); + if (AH->remoteVersion < 140000) + { + /* pre-v14, the only method was pglz */ + toast_compression = pg_strdup("pglz"); + } + else + { + PGresult *res; + + res = ExecuteSqlQueryForSingleRow(AH, "SHOW default_toast_compression"); + toast_compression = pg_strdup(PQgetvalue(res, 0, 0)); + PQclear(res); + } qry = createPQExpBuffer(); appendPQExpBufferStr(qry, "SET default_toast_compression = "); @@ -3363,9 +3373,8 @@ dumpToastCompression(Archive *AH) * Also save it in AH->default_toast_compression, in case we're doing * plain text dump. */ - AH->default_toast_compression = pg_strdup(toast_compression); + AH->default_toast_compression = toast_compression; - PQclear(res); destroyPQExpBuffer(qry); }