postgres.git / summary / log / commit / refs

commit    54bb91c30e3964fd81059e6b02e377cc9dd2d64c
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Tue Mar 30 14:57:57 2021 +0000

    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);
 }
 


[parent: ed934d4fa30f]