Aidar Imamov wrote 2025-05-21 00:32:
Ashutosh Bapat wrote 2023-03-28 15:58:
Bumping it to attract some attention.
On Tue, Mar 21, 2023 at 12:51 PM Ashutosh Bapat
wrote:
Hi,
Hash table scans (seq_scan_table/level) are cleaned up at the end of
a
transaction in AtEOXact_HashTables(). If a
ounter if we find scans that started outside of the
current
transaction at the end. I have to admit, though, that I can't
immediately
say what other implications this might have or what else we need to
watch
out for if we try this.
Maybe any thoughts on that?
regards,
Aidar Imamov
diff --git a/c
object or marks
them as dirty... I can't really say for sure about that. And in that
context, I'd
suggest referring to that awesome statement in the documentation: "If in
doubt,
functions should be labeled as UNSAFE, which is the default."
regards,
Aidar Imamov
k. In addition, this
would
remove the "flushed" parameter from the EvictUnpinnedBuffer() function.
Because if we explicitly call LockBufHdr() outside of
EvictUnpinnedBuffer(),
we can already know in advance whether the buffer is dirty or not.
The same applies to the suggestion to retrieve "flushed" count from the
pg_buffercache_evict() call. We cannot say this for certain, but we can
determine whether the buffer was dirty.
regards,
Aidar Imamov
dit the elog text to: "bad shared buffer ID" - just to clarify
the case when
provided buffer number is negative (local buffer number).
pg_buffercache_mark_dirty_all():
Maybe also edit the comment to: "Try to mark all the shared buffers as
dirty."?
bufmgr.h:
I think it might be a good idea to follow the Postgres formatting style
and move the
function's arguments to the next line if they exceed 80 characters.
regards,
Aidar Imamov
r of the
BufTagMatchesRelFileLocator()
and LockBufHdr() calls for improved efficiency (as mentioned in the
comment on
the BufTagMatchesRelFileLocator() call in the DropRelationBuffers()
function in
bufmgr.c).
And it maybe useful also to add BUT_STATE_GET_REFCOUNT == 0 precheck
before calling
EvictUnpinnedBuffer()?
regards,
Aidar Imamov
