rather than returning NULL for some-but-not-all failures as they used to.
Remove now-redundant tests for NULL from call sites.

We had to do something about this because many call sites were failing to
check for NULL; and changing it like this seems a lot more useful and
mistake-proof than adding checks to the call sites without them.

This uses the same infrastructure with EXPLAIN BUFFERS to support
{shared|local}_blks_{hit|read|written} andtemp_blks_{read|written}
columns in the pg_stat_statements view. The dumped file format
also updated.

Thanks to Robert Haas for the review.

PL/pgSQL function within an exception handler. Make sure we use the right
resource owner when we create the tuplestore to hold returned tuples.

Simplify tuplestore API so that the caller doesn't need to be in the right
memory context when calling tuplestore_put* functions. tuplestore.c
automatically switches to the memory context used when the tuplestore was
created. Tuplesort was already modified like this earlier. This patch also
removes the now useless MemoryContextSwitch calls from callers.

Report by Aleksei on pgsql-bugs on Dec 22 2009. Backpatch to 8.1, like
the previous patch that broke this.

and use it to extend contrib/pg_stat_statements to track utility commands.

Itagaki Takahiro, reviewed by Euler Taveira de Oliveira.

This patch also removes buffer-usage statistics from the track_counts
output, since this (or the global server statistics) is deemed to be a better
interface to this information.

Itagaki Takahiro, reviewed by Euler Taveira de Oliveira.

Add ProcessUtility_hook() to handle all DDL to
contrib/pg_stat_statements.

Add ProcessUtility_hook() to handle all DDL to contrib/pg_stat_statements.

Itagaki Takahiro

We should not try to load old statistics when re-attaching to existing
shared memory.  Per bug #4941.

Itagaki Takahiro

provided by Andrew.

get listed in custom_variable_classes.

statistics.

Takahiro Itagaki