Obtain table locks as soon as practical during pg_dump.

For some reason, when we (I) added table lock acquisition to pg_dump,
we didn't think about making it happen as soon as possible after the
start of the transaction.  What with subsequent additions, there was
actually quite a lot going on before we got around to that; which sort
of defeats the purpose.  Rearrange the order of calls in dumpSchema()
to close the risk window as much as we easily can.  Back-patch to all
supported branches.
This commit is contained in:
Tom Lane 2011-06-17 18:19:02 -04:00
parent 062780ec35
commit 68d977a737
1 changed files with 11 additions and 5 deletions

View File

@ -105,6 +105,17 @@ getSchemaData(int *numTablesPtr)
write_msg(NULL, "reading schemas\n");
getNamespaces(&numNamespaces);
/*
* getTables should be done as soon as possible, so as to minimize the
* window between starting our transaction and acquiring per-table locks.
* However, we have to do getNamespaces first because the tables get
* linked to their containing namespaces during getTables.
*/
if (g_verbose)
write_msg(NULL, "reading user-defined tables\n");
tblinfo = getTables(&numTables);
tblinfoindex = buildIndexArray(tblinfo, numTables, sizeof(TableInfo));
if (g_verbose)
write_msg(NULL, "reading extensions\n");
extinfo = getExtensions(&numExtensions);
@ -183,11 +194,6 @@ getSchemaData(int *numTablesPtr)
write_msg(NULL, "reading type casts\n");
getCasts(&numCasts);
if (g_verbose)
write_msg(NULL, "reading user-defined tables\n");
tblinfo = getTables(&numTables);
tblinfoindex = buildIndexArray(tblinfo, numTables, sizeof(TableInfo));
if (g_verbose)
write_msg(NULL, "reading table inheritance information\n");
inhinfo = getInherits(&numInherits);