to 'Size' (that is, size_t), and install overflow detection checks in it.
This allows us to remove the former arbitrary restrictions on NBuffers
etc. It won't make any difference in a 32-bit machine, but in a 64-bit
machine you could theoretically have terabytes of shared buffers.
(How efficiently we could manage 'em remains to be seen.) Similarly,
num_temp_buffers, work_mem, and maintenance_work_mem can be set above
2Gb on a 64-bit machine. Original patch from Koichi Suzuki, additional
work by moi.
chdir into PGDATA and subsequently use relative paths instead of absolute
paths to access all files under PGDATA. This seems to give a small
performance improvement, and it should make the system more robust
against naive DBAs doing things like moving a database directory that
has a live postmaster in it. Per recent discussion.
spotted by Qingqing Zhou. The HASH_ENTER action now automatically
fails with elog(ERROR) on out-of-memory --- which incidentally lets
us eliminate duplicate error checks in quite a bunch of places. If
you really need the old return-NULL-on-out-of-memory behavior, you
can ask for HASH_ENTER_NULL. But there is now an Assert in that path
checking that you aren't hoping to get that behavior in a palloc-based
hash table.
Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions,
which were not being used anywhere anymore, and were surely too ugly
and unsafe to want to see revived again.
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
There are various things left to do: contrib dbsize and oid2name modules
need work, and so does the documentation. Also someone should think about
COMMENT ON TABLESPACE and maybe RENAME TABLESPACE. Also initlocation is
dead, it just doesn't know it yet.
Gavin Sherry and Tom Lane.
Ward's report that it can still happen in RC2 forces me to realize that
this is not a can't-happen condition after all, and that the compaction
code had better cope rather than panicking.
at database shutdown, and then load it again at database startup. This
preserves our hard-won knowledge of free space across restarts (given
an orderly shutdown, that is).
Adjustable threshold is gone in favor of keeping track of total requested
page storage and doling out proportional fractions to each relation
(with a minimum amount per relation, and some quantization of the results
to avoid thrashing with small changes in page counts). Provide special-
case code for indexes so as not to waste space storing useless page
free space counts. Restructure internal data storage to be a flat array
instead of list-of-chunks; this may cost a little more work in data
copying when reorganizing, but allows binary search to be used during
lookup_fsm_page_entry().
removes any empty chunks, the chunk previously added won't be there
anymore, so it's possible there is zero free space in the rel's page list
afterwards. Must loop back and rerun the part that adds a chunk to
the list.
readability. Bizarre '(long *) TRUE' return convention is gone,
in favor of just raising an error internally in dynahash.c when
we detect hashtable corruption. HashTableWalk is gone, in favor
of using hash_seq_search directly, since it had no hope of working
with non-LONGALIGNable datatypes. Simplify some other code that was
made undesirably grotty by promixity to HashTableWalk.
portability issues). Caller-visible data structures are now allocated
on MAXALIGN boundaries, allowing safe use of datatypes wider than 'long'.
Rejigger hash_create API so that caller specifies size of key and
total size of entry, not size of key and size of rest of entry.
This simplifies life considerably since each number is just a sizeof(),
and padding issues etc. are taken care of automatically.
existing lock manager and spinlocks: it understands exclusive vs shared
lock but has few other fancy features. Replace most uses of spinlocks
with lightweight locks. All remaining uses of spinlocks have very short
lock hold times (a few dozen instructions), so tweak spinlock backoff
code to work efficiently given this assumption. All per my proposal on
pghackers 26-Sep-01.
useful as yet, since its primary source of information is (full) VACUUM,
which makes a concerted effort to get rid of free space before telling
the map about it ... next stop is concurrent VACUUM ...
stub) into the rest of the system. Adopt a cleaner approach to preventing
deadlock in concurrent heap_updates: allow RelationGetBufferForTuple to
select any page of the rel, and put the onus on it to lock both buffers
in a consistent order. Remove no-longer-needed isExtend hack from
API of ReleaseAndReadBuffer.
do anything yet, but it has the necessary connections to initialization
and so forth. Make some gestures towards allowing number of blocks in
a relation to be BlockNumber, ie, unsigned int, rather than signed int.
(I doubt I got all the places that are sloppy about it, yet.) On the
way, replace the hardwired NLOCKS_PER_XACT fudge factor with a GUC
variable.
