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2005-12-29Get rid of the SpinLockAcquire/SpinLockAcquire_NoHoldoff distinctionTom Lane
in favor of having just one set of macros that don't do HOLD/RESUME_INTERRUPTS (hence, these correspond to the old SpinLockAcquire_NoHoldoff case). Given our coding rules for spinlock use, there is no reason to allow CHECK_FOR_INTERRUPTS to be done while holding a spinlock, and also there is no situation where ImmediateInterruptOK will be true while holding a spinlock. Therefore doing HOLD/RESUME_INTERRUPTS while taking/releasing a spinlock is just a waste of cycles. Qingqing Zhou and Tom Lane.
2005-12-28Arrange to set the LC_XXX environment variables to match our localeTom Lane
setup. This protects against undesired changes in locale behavior if someone carelessly does setlocale(LC_ALL, "") (and we know who you are, perl guys).
2005-12-25I have added these macros to c.h:Bruce Momjian
#define HIGHBIT (0x80) #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT) and removed CSIGNBIT and mapped it uses to HIGHBIT. I have also added uses for IS_HIGHBIT_SET where appropriate. This change is purely for code clarity.
2005-12-22Adjust string comparison so that only bitwise-equal strings are consideredTom Lane
equal: if strcoll claims two strings are equal, check it with strcmp, and sort according to strcmp if not identical. This fixes inconsistent behavior under glibc's hu_HU locale, and probably under some other locales as well. Also, take advantage of the now-well-defined behavior to speed up texteq, textne, bpchareq, bpcharne: they may as well just do a bitwise comparison and not bother with strcoll at all. NOTE: affected databases may need to REINDEX indexes on text columns to be sure they are self-consistent.
2005-12-11Divide the lock manager's shared state into 'partitions', so as toTom Lane
reduce contention for the former single LockMgrLock. Per my recent proposal. I set it up for 16 partitions, but on a pgbench test this gives only a marginal further improvement over 4 partitions --- we need to test more scenarios to choose the number of partitions.
2005-12-07Push the responsibility for handling ignore_killed_tuples down intoTom Lane
_bt_checkkeys(), instead of checking it in the top-level nbtree.c routines as formerly. This saves a little bit of loop overhead, but more importantly it lets us skip performing the index key comparisons for dead tuples.
2005-12-07A couple of tiny performance hacks in _bt_step(). Remove PageIsEmptyTom Lane
checks, which were once needed because PageGetMaxOffsetNumber would fail on empty pages, but are now just redundant. Also, don't set up local variables that aren't needed in the fast path --- most of the time, we only need to advance offnum and not step across a page boundary. Motivated by noticing _bt_step at the top of OProfile profile for a pgbench run.
2005-12-06Get rid of slru.c's hardwired insistence on a fixed number of slots perTom Lane
SLRU area. The number of slots is still a compile-time constant (someday we might want to change that), but at least it's a different constant for each SLRU area. Increase number of subtrans buffers to 32 based on experimentation with a heavily subtrans-bashing test case, and increase number of multixact member buffers to 16, since it's obviously silly for it not to be at least twice the number of multixact offset buffers.
2005-12-06Arrange for read-only accesses to SLRU page buffers to take only a sharedTom Lane
lock, not exclusive, if the desired page is already in memory. This can be demonstrated to be a significant win on the pg_subtrans cache when there is a large window of open transactions. It should be useful for pg_clog as well. I didn't try to make GetMultiXactIdMembers() use the code, as that would have taken some restructuring, and what with the local cache for multixact contents it probably wouldn't really make a difference. Per my recent proposal.
2005-12-03Tweak indexscan machinery to avoid taking an AccessShareLock on an indexTom Lane
if we already have a stronger lock due to the index's table being the update target table of the query. Same optimization I applied earlier at the table level. There doesn't seem to be much interest in the more radical idea of not locking indexes at all, so do what we can ...
2005-11-26Some marginal additional hacking to shave a few more cycles offTom Lane
heapgettup.
2005-11-26Change seqscan logic so that we check visibility of all tuples on a pageTom Lane
when we first read the page, rather than checking them one at a time. This allows us to take and release the buffer content lock just once per page, instead of once per tuple. Since it's a shared lock the contention penalty for holding the lock longer shouldn't be too bad. We can safely do this only when using an MVCC snapshot; else the assumption that visibility won't change over time is uncool. Therefore there are now two code paths depending on the snapshot type. I also made the same change in nodeBitmapHeapscan.c, where it can be done always because we only support MVCC snapshots for bitmap scans anyway. Also make some incidental cleanups in the APIs of these functions. Per a suggestion from Qingqing Zhou.
2005-11-22Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian
comment line where output as too long, and update typedefs for /lib directory. Also fix case where identifiers were used as variable names in the backend, but as typedefs in ecpg (favor the backend for indenting). Backpatch to 8.1.X.
2005-11-20Remove the t_datamcxt field of HeapTupleData. This was introduced forTom Lane
the convenience of tuptoaster.c and is no longer needed, so may as well get rid of some small amount of overhead.
2005-11-20Modify tuptoaster's API so that it does not try to modify the passedTom Lane
tuple in-place, but instead passes back an all-new tuple structure if any changes are needed. This is a much cleaner and more robust solution for the bug discovered by Alexey Beschiokov; accordingly, revert the quick hack I installed yesterday. With this change, HeapTupleData.t_datamcxt is no longer needed; will remove it in a separate commit in HEAD only.
2005-11-07R-tree is dead ... long live GiST.Tom Lane
2005-11-06Add simple sanity checks on newly-read pages to GiST, too.Tom Lane
2005-11-06Add defenses to btree and hash index AMs to do simple sanity checksTom Lane
on every index page they read; in particular to catch the case of an all-zero page, which PageHeaderIsValid allows to pass. It turns out hash already had this idea, but it was just Assert()ing things rather than doing a straight error check, and the Asserts were partially redundant with PageHeaderIsValid anyway. Per recent failure example from Jim Nasby. (gist still needs the same treatment.)
2005-11-05Clean up representation of SLRU page state. This is the cleaner fixTom Lane
for the SLRU race condition that I posted a few days ago, but we decided not to use in 8.1 and older branches.
2005-11-03Rename the members of CommandDest enum so they don't collide with other uses ofAlvaro Herrera
those names. (Debug and None were pretty bad names anyway.) I hope I catched all uses of the names in comments too.
2005-11-03Fix longstanding race condition in transaction log management: there was aTom Lane
very narrow window in which SimpleLruReadPage or SimpleLruWritePage could think that I/O was needed when it wasn't (and indeed the buffer had already been assigned to another page). This would result in an Assert failure if Asserts were enabled, and probably in silent data corruption if not. Reported independently by Jim Nasby and Robert Creager. I intend a more extensive fix when 8.2 development starts, but this is a reasonably low-impact patch for the existing branches.
2005-10-29Message correctionsPeter Eisentraut
2005-10-28Reorder code so that we don't have to hold a critical section whileTom Lane
reserving SLRU space for a new MultiXact. The original coding would have treated out-of-disk-space as a PANIC condition, which is unnecessary.
2005-10-28Fix race condition in multixact code: it's possible to try to read aTom Lane
multixact's starting offset before the offset has been stored into the SLRU file. A simple fix would be to hold the MultiXactGenLock until the offset has been stored, but that looks like a big concurrency hit. Instead rely on knowledge that unset offsets will be zero, and loop when we see a zero. This requires a little extra hacking to ensure that zero is never a valid value for the offset. Problem reported by Matteo Beccati, fix ideas from Martijn van Oosterhout, Alvaro Herrera, and Tom Lane.
2005-10-22Make code for selecting default WAL sync method less confusing.Tom Lane
2005-10-19Better solution to the problem of labeling whole-row Datums that areTom Lane
generated from subquery outputs: use the type info stored in the Var itself. To avoid making ExecEvalVar and slot_getattr more complex and slower, I split out the whole-row case into a separate ExecEval routine.
2005-10-19Ensure that the Datum generated from a whole-row Var contains validTom Lane
type ID information even when it's a record type. This is needed to handle whole-row Vars referencing subquery outputs. Per example from Richard Huxton.
2005-10-18A few trivial code cleanups motivated by reading warnings generatedTom Lane
by a recent HP C compiler. Mostly, get rid of useless local variables that are assigned to but never used.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-10-13This makes the error messages for PREPARE TRANSACTION, COMMIT PREPAREDBruce Momjian
etc. match the docs, which talk about "transaction identifier" not "gid" or "global transaction identifier". Steve Woodcock
2005-10-13Back out this because of fear of changing error strings:Bruce Momjian
This makes the error messages for PREPARE TRANSACTION, COMMIT PREPARED etc. match the docs, which talk about "transaction identifier" not "gid" or "global transaction identifier". Steve Woodcock
2005-10-13This makes the error messages for PREPARE TRANSACTION, COMMIT PREPAREDBruce Momjian
etc. match the docs, which talk about "transaction identifier" not "gid" or "global transaction identifier". Steve Woodcock
2005-10-12Fix longstanding bug found by Atsushi Ogawa: _bt_check_unique would markTom Lane
the wrong buffer dirty when trying to kill a dead index entry that's on a page after the one it started on. No risk of data corruption, just inefficiency, but still a bug.
2005-10-06Revise pgstats stuff to fix the problems with not counting accessesTom Lane
generated by bitmap index scans. Along the way, simplify and speed up the code for counting sequential and index scans; it was both confusing and inefficient to be taking care of that in the per-tuple loops, IMHO. initdb forced because of internal changes in pg_stat view definitions.
2005-10-03Expand pg_control information so that we can verify that the databaseTom Lane
was created on a machine with alignment rules and floating-point format similar to the current machine. Per recent discussion, this seems like a good idea with the increasing prevalence of 32/64 bit environments.
2005-09-24Clean up possibly-uninitialized-variable warnings reported by gcc 4.x.Tom Lane
2005-09-22pgindent new GIST index code, per request from Tom.Bruce Momjian
2005-09-22Adjust GiST error messages to conform to message style guidelines.Tom Lane
2005-09-16Small fixesTeodor Sigaev
2005-09-15Copy-editing for GiST README.Neil Conway
2005-09-15Readme about GiST's algorithmsTeodor Sigaev
2005-09-02Clean up a couple of ad-hoc computations of the maximum number of tuplesTom Lane
on a page, as suggested by ITAGAKI Takahiro. Also, change a few places that were using some other estimates of max-items-per-page to consistently use MaxOffsetNumber. This is conservatively large --- we could have used the new MaxHeapTuplesPerPage macro, or a similar one for index tuples --- but those places are simply declaring a fixed-size buffer and assuming it will work, rather than actively testing for overrun. It seems safer to size these buffers in a way that can't overflow even if the page is corrupt.
2005-08-29Reduce default value of max_prepared_transactions from 50 to 5. ThisTom Lane
saves nearly 700kB in the default shared memory segment size, which seems worthwhile, and it is a feature that many users won't use anyway. Per Heikki's argument, there is no point in a compromise value --- those who are using 2PC at all will probably want it at least equal to max_connections. But we can't set it to zero by default without breaking the prepared_xacts regression test.
2005-08-22Rewrite gather-write patch into something less obviously bolted onTom Lane
after the fact. Fix bug with incorrect test for whether we are at end of logfile segment. Arrange for writes triggered by XLogInsert's is-cache-more-than-half-full test to synchronize with the cache boundaries, so that in long transactions we tend to write alternating halves of the cache rather than randomly chosen portions of it; this saves one more write syscall per cache load.
2005-08-22Improve xid wraparound message (the server isn't really shut down, justBruce Momjian
not accepting queries). errmsg("database is not accepting queries to avoid wraparound data loss in database \"%s\"", errhint("Stop the postmaster and use a standalone backend to VACUUM database \"%s\".",
2005-08-22Fix some inconsistent choices of datatypes in xlog.c. Make bufferTom Lane
indexes all be int, rather than variously int, uint16 and uint32; add some casts where necessary to support large buffer arrays.
2005-08-20Seems that the childXids list would be better based on Oid lists thanTom Lane
integer lists.
2005-08-20Convert the arithmetic for shared memory size calculation from 'int'Tom Lane
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.
2005-08-20Make GetMultiXactIdMembers() a public function.Tatsuo Ishii
2005-08-20Repair problems with VACUUM destroying t_ctid chains too soon, and withTom Lane
insufficient paranoia in code that follows t_ctid links. (We must do both because even with VACUUM doing it properly, the intermediate state with a dangling t_ctid link is visible concurrently during lazy VACUUM, and could be seen afterwards if either type of VACUUM crashes partway through.) Also try to improve documentation about what's going on. Patch is a bit bulky because passing the XMAX information around required changing the APIs of some low-level heapam.c routines, but it's not conceptually very complicated. Per trouble report from Teodor and subsequent analysis. This needs to be back-patched, but I'll do that after 8.1 beta is out.