summaryrefslogtreecommitdiff
path: root/src/backend/bootstrap
AgeCommit message (Collapse)Author
2016-04-08Revert CREATE INDEX ... INCLUDING ...Teodor Sigaev
It's not ready yet, revert two commits 690c543550b0d2852060c18d270cdb534d339d9a - unstable test output 386e3d7609c49505e079c40c65919d99feb82505 - patch itself
2016-04-08CREATE INDEX ... INCLUDING (column[, ...])Teodor Sigaev
Now indexes (but only B-tree for now) can contain "extra" column(s) which doesn't participate in index structure, they are just stored in leaf tuples. It allows to use index only scan by using single index instead of two or more indexes. Author: Anastasia Lubennikova with minor editorializing by me Reviewers: David Rowley, Peter Geoghegan, Jeff Janes
2016-03-10Provide much better wait information in pg_stat_activity.Robert Haas
When a process is waiting for a heavyweight lock, we will now indicate the type of heavyweight lock for which it is waiting. Also, you can now see when a process is waiting for a lightweight lock - in which case we will indicate the individual lock name or the tranche, as appropriate - or for a buffer pin. Amit Kapila, Ildus Kurbangaliev, reviewed by me. Lots of helpful discussion and suggestions by many others, including Alexander Korotkov, Vladimir Borodin, and many others.
2016-01-28Fix typos in comments and docFujii Masao
overriden -> overridden The misspelling in create_extension.sgml was introduced in b67aaf2, so no need to backpatch.
2016-01-02Update copyright for 2016Bruce Momjian
Backpatch certain files through 9.1
2015-05-23pgindent run for 9.5Bruce Momjian
2015-05-15Move strategy numbers to include/access/stratnum.hAlvaro Herrera
For upcoming BRIN opclasses, it's convenient to have strategy numbers defined in a single place. Since there's nothing appropriate, create it. The StrategyNumber typedef now lives there, as well as existing strategy numbers for B-trees (from skey.h) and R-tree-and-friends (from gist.h). skey.h is forced to include stratnum.h because of the StrategyNumber typedef, but gist.h is not; extensions that currently rely on gist.h for rtree strategy numbers might need to add a new A few .c files can stop including skey.h and/or gist.h, which is a nice side benefit. Per discussion: https://www.postgresql.org/message-id/20150514232132.GZ2523@alvh.no-ip.org Authored by Emre Hasegeli and Álvaro. (It's not clear to me why bootscanner.l has any #include lines at all.)
2015-05-09Add new OID alias type regnamespaceAndrew Dunstan
Catalog version bumped Kyotaro HORIGUCHI
2015-05-09Add new OID alias type regroleAndrew Dunstan
The new type has the scope of whole the database cluster so it doesn't behave the same as the existing OID alias types which have database scope, concerning object dependency. To avoid confusion constants of the new type are prohibited from appearing where dependencies are made involving it. Also, add a note to the docs about possible MVCC violation and optimization issues, which are general over the all reg* types. Kyotaro Horiguchi
2015-04-28Protect against multixact members wraparoundAlvaro Herrera
Multixact member files are subject to early wraparound overflow and removal: if the average multixact size is above a certain threshold (see note below) the protections against offset overflow are not enough: during multixact truncation at checkpoint time, some pg_multixact/members files would be removed because the server considers them to be old and not needed anymore. This leads to loss of files that are critical to interpret existing tuples's Xmax values. To protect against this, since we don't have enough info in pg_control and we can't modify it in old branches, we maintain shared memory state about the oldest value that we need to keep; we use this during new multixact creation to abort if an old still-needed file would get overwritten. This value is kept up to date by checkpoints, which makes it not completely accurate but should be good enough. We start emitting warnings sometime earlier, so that the eventual multixact-shutdown doesn't take DBAs completely by surprise (more precisely: once 20 members SLRU segments are remaining before shutdown.) On troublesome average multixact size: The threshold size depends on the multixact freeze parameters. The oldest age is related to the greater of multixact_freeze_table_age and multixact_freeze_min_age: anything older than that should be removed promptly by autovacuum. If autovacuum is keeping up with multixact freezing, the troublesome multixact average size is (2^32-1) / Max(freeze table age, freeze min age) or around 28 members per multixact. Having an average multixact size larger than that will eventually cause new multixact data to overwrite the data area for older multixacts. (If autovacuum is not able to keep up, or there are errors in vacuuming, the actual maximum is multixact_freeeze_max_age instead, at which point multixact generation is stopped completely. The default value for this limit is 400 million, which means that the multixact size that would cause trouble is about 10 members). Initial bug report by Timothy Garnett, bug #12990 Backpatch to 9.3, where the problem was introduced. Authors: Álvaro Herrera, Thomas Munro Reviews: Thomas Munro, Amit Kapila, Robert Haas, Kevin Grittner
2015-03-03Change many routines to return ObjectAddress rather than OIDAlvaro Herrera
The changed routines are mostly those that can be directly called by ProcessUtilitySlow; the intention is to make the affected object information more precise, in support for future event trigger changes. Originally it was envisioned that the OID of the affected object would be enough, and in most cases that is correct, but upon actually implementing the event trigger changes it turned out that ObjectAddress is more widely useful. Additionally, some command execution routines grew an output argument that's an object address which provides further info about the executed command. To wit: * for ALTER DOMAIN / ADD CONSTRAINT, it corresponds to the address of the new constraint * for ALTER OBJECT / SET SCHEMA, it corresponds to the address of the schema that originally contained the object. * for ALTER EXTENSION {ADD, DROP} OBJECT, it corresponds to the address of the object added to or dropped from the extension. There's no user-visible change in this commit, and no functional change either. Discussion: 20150218213255.GC6717@tamriel.snowman.net Reviewed-By: Stephen Frost, Andres Freund
2015-02-22Get rid of multiple applications of transformExpr() to the same tree.Tom Lane
transformExpr() has for many years had provisions to do nothing when applied to an already-transformed expression tree. However, this was always ugly and of dubious reliability, so we'd be much better off without it. The primary historical reason for it was that gram.y sometimes returned multiple links to the same subexpression, which is no longer true as of my BETWEEN fixes. We'd also grown some lazy hacks in CREATE TABLE LIKE (failing to distinguish between raw and already-transformed index specifications) and one or two other places. This patch removes the need for and support for re-transforming already transformed expressions. The index case is dealt with by adding a flag to struct IndexStmt to indicate that it's already been transformed; which has some benefit anyway in that tablecmds.c can now Assert that transformation has happened rather than just assuming. The other main reason was some rather sloppy code for array type coercion, which can be fixed (and its performance improved too) by refactoring. I did leave transformJoinUsingClause() still constructing expressions containing untransformed operator nodes being applied to Vars, so that transformExpr() still has to allow Var inputs. But that's a much narrower, and safer, special case than before, since Vars will never appear in a raw parse tree, and they don't have any substructure to worry about. In passing fix some oversights in the patch that added CREATE INDEX IF NOT EXISTS (missing processing of IndexStmt.if_not_exists). These appear relatively harmless, but still sloppy coding practice.
2015-02-21Allow forcing nullness of columns during bootstrap.Andres Freund
Bootstrap determines whether a column is null based on simple builtin rules. Those work surprisingly well, but nonetheless a few existing columns aren't set correctly. Additionally there is at least one patch sent to hackers where forcing the nullness of a column would be helpful. The boostrap format has gained FORCE [NOT] NULL for this, which will be emitted by genbki.pl when BKI_FORCE_(NOT_)?NULL is specified for a column in a catalog header. This patch doesn't change the marking of any existing columns. Discussion: 20150215170014.GE15326@awork2.anarazel.de
2015-02-02Add new function BackgroundWorkerInitializeConnectionByOid.Robert Haas
Sometimes it's useful for a background worker to be able to initialize its database connection by OID rather than by name, so provide a way to do that.
2015-01-14Remove some dead IsUnderPostmaster code from bootstrap.c.Andres Freund
Since commit 626eb021988a2 has introduced the auxiliary process infrastructure, bootstrap_signals() was never used when forked from postmaster. Remove the IsUnderPostmaster specific code, and add a appropriate assertion.
2015-01-14Commonalize process startup code.Andres Freund
Move common code, that was duplicated in every postmaster child/every standalone process, into two functions in miscinit.c. Not only does that already result in a fair amount of net code reduction but it also makes it much easier to remove more duplication in the future. The prime motivation wasn't code deduplication though, but easier addition of new common code.
2015-01-06Update copyright for 2015Bruce Momjian
Backpatch certain files through 9.0
2014-12-16Fix off-by-one loop count in MapArrayTypeName, and get rid of static array.Tom Lane
MapArrayTypeName would copy up to NAMEDATALEN-1 bytes of the base type name, which of course is wrong: after prepending '_' there is only room for NAMEDATALEN-2 bytes. Aside from being the wrong result, this case would lead to overrunning the statically allocated work buffer. This would be a security bug if the function were ever used outside bootstrap mode, but it isn't, at least not in any currently supported branches. Aside from fixing the off-by-one loop logic, this patch gets rid of the static work buffer by having MapArrayTypeName pstrdup its result; the sole caller was already doing that, so this just requires moving the pstrdup call. This saves a few bytes but mainly it makes the API a lot cleaner. Back-patch on the off chance that there is some third-party code using MapArrayTypeName with less-secure input. Pushing pstrdup into the function should not cause any serious problems for such hypothetical code; at worst there might be a short term memory leak. Per Coverity scanning.
2014-05-28Revert "Fix bogus %name-prefix option syntax in all our Bison files."Tom Lane
This reverts commit 45b7abe59e9485657ac9380f35d2d917dd0da25b. It turns out that the %name-prefix syntax without "=" does not work at all in pre-2.4 Bison. We are not prepared to make such a large jump in minimum required Bison version just to suppress a warning message in a version hardly any developers are using yet. When 3.0 gets more popular, we'll figure out a way to deal with this. In the meantime, BISONFLAGS=-Wno-deprecated is recommendable for anyone using 3.0 who doesn't want to see the warning.
2014-05-28Fix bogus %name-prefix option syntax in all our Bison files.Tom Lane
%name-prefix doesn't use an "=" sign according to the Bison docs, but it silently accepted one anyway, until Bison 3.0. This was originally a typo of mine in commit 012abebab1bc72043f3f670bf32e91ae4ee04bd2, and we seem to have slavishly copied the error into all the other grammar files. Per report from Vik Fearing; analysis by Peter Eisentraut. Back-patch to all active branches, since somebody might try to build a back branch with up-to-date tools.
2014-05-06pgindent run for 9.4Bruce Momjian
This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
2014-02-17Avoid repeated name lookups during table and index DDL.Robert Haas
If the name lookups come to different conclusions due to concurrent activity, we might perform some parts of the DDL on a different table than other parts. At least in the case of CREATE INDEX, this can be used to cause the permissions checks to be performed against a different table than the index creation, allowing for a privilege escalation attack. This changes the calling convention for DefineIndex, CreateTrigger, transformIndexStmt, transformAlterTableStmt, CheckIndexCompatible (in 9.2 and newer), and AlterTable (in 9.1 and older). In addition, CheckRelationOwnership is removed in 9.2 and newer and the calling convention is changed in older branches. A field has also been added to the Constraint node (FkConstraint in 8.4). Third-party code calling these functions or using the Constraint node will require updating. Report by Andres Freund. Patch by Robert Haas and Andres Freund, reviewed by Tom Lane. Security: CVE-2014-0062
2014-02-15Centralize getopt-related declarations in a new header file pg_getopt.h.Tom Lane
We used to have externs for getopt() and its API variables scattered all over the place. Now that we find we're going to need to tweak the variable declarations for Cygwin, it seems like a good idea to have just one place to tweak. In this commit, the variables are declared "#ifndef HAVE_GETOPT_H". That may or may not work everywhere, but we'll soon find out. Andres Freund
2014-01-11Fix possible crashes due to using elog/ereport too early in startup.Tom Lane
Per reports from Andres Freund and Luke Campbell, a server failure during set_pglocale_pgservice results in a segfault rather than a useful error message, because the infrastructure needed to use ereport hasn't been initialized; specifically, MemoryContextInit hasn't been called. One known cause of this is starting the server in a directory it doesn't have permission to read. We could try to prevent set_pglocale_pgservice from using anything that depends on palloc or elog, but that would be messy, and the odds of future breakage seem high. Moreover there are other things being called in main.c that look likely to use palloc or elog too --- perhaps those things shouldn't be there, but they are there today. The best solution seems to be to move the call of MemoryContextInit to very early in the backend's real main() function. I've verified that an elog or ereport occurring immediately after that is now capable of sending something useful to stderr. I also added code to elog.c to print something intelligible rather than just crashing if MemoryContextInit hasn't created the ErrorContext. This could happen if MemoryContextInit itself fails (due to malloc failure), and provides some future-proofing against someone trying to sneak in new code even earlier in server startup. Back-patch to all supported branches. Since we've only heard reports of this type of failure recently, it may be that some recent change has made it more likely to see a crash of this kind; but it sure looks like it's broken all the way back.
2014-01-07Update copyright for 2014Bruce Momjian
Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
2013-12-18Allow on-detach callbacks for dynamic shared memory segments.Robert Haas
Just as backends must clean up their shared memory state (releasing lwlocks, buffer pins, etc.) before exiting, they must also perform any similar cleanups related to dynamic shared memory segments they have mapped before unmapping those segments. So add a mechanism to ensure that. Existing on_shmem_exit hooks include both "user level" cleanup such as transaction abort and removal of leftover temporary relations and also "low level" cleanup that forcibly released leftover shared memory resources. On-detach callbacks should run after the first group but before the second group, so create a new before_shmem_exit function for registering the early callbacks and keep on_shmem_exit for the regular callbacks. (An earlier draft of this patch added an additional argument to on_shmem_exit, but that had a much larger footprint and probably a substantially higher risk of breaking third party code for no real gain.) Patch by me, reviewed by KaiGai Kohei and Andres Freund.
2013-11-03Prevent memory leaks from accumulating across printtup() calls.Tom Lane
Historically, printtup() has assumed that it could prevent memory leakage by pfree'ing the string result of each output function and manually managing detoasting of toasted values. This amounts to assuming that datatype output functions never leak any memory internally; an assumption we've already decided to be bogus elsewhere, for example in COPY OUT. range_out in particular is known to leak multiple kilobytes per call, as noted in bug #8573 from Godfried Vanluffelen. While we could go in and fix that leak, it wouldn't be very notationally convenient, and in any case there have been and undoubtedly will again be other leaks in other output functions. So what seems like the best solution is to run the output functions in a temporary memory context that can be reset after each row, as we're doing in COPY OUT. Some quick experimentation suggests this is actually a tad faster than the retail pfree's anyway. This patch fixes all the variants of printtup, except for debugtup() which is used in standalone mode. It doesn't seem worth worrying about query-lifespan leaks in standalone mode, and fixing that case would be a bit tedious since debugtup() doesn't currently have any startup or shutdown functions. While at it, remove manual detoast management from several other output-function call sites that had copied it from printtup(). This doesn't make a lot of difference right now, but in view of recent discussions about supporting "non-flattened" Datums, we're going to want that code gone eventually anyway. Back-patch to 9.2 where range_out was introduced. We might eventually decide to back-patch this further, but in the absence of known major leaks in older output functions, I'll refrain for now.
2013-10-13Add use of asprintf()Peter Eisentraut
Add asprintf(), pg_asprintf(), and psprintf() to simplify string allocation and composition. Replacement implementations taken from NetBSD. Reviewed-by: Álvaro Herrera <alvherre@2ndquadrant.com> Reviewed-by: Asif Naeem <anaeem.it@gmail.com>
2013-10-09Centralize effective_cache_size default settingBruce Momjian
2013-10-08Again move function where we set effective_cache_size's defaultBruce Momjian
2013-10-08Move new effective_cache_size functionBruce Momjian
Previously set_default_effective_cache_size() could not handle fork, non-fork, and bootstrap cases.
2013-07-02Use an MVCC snapshot, rather than SnapshotNow, for catalog scans.Robert Haas
SnapshotNow scans have the undesirable property that, in the face of concurrent updates, the scan can fail to see either the old or the new versions of the row. In many cases, we work around this by requiring DDL operations to hold AccessExclusiveLock on the object being modified; in some cases, the existing locking is inadequate and random failures occur as a result. This commit doesn't change anything related to locking, but will hopefully pave the way to allowing lock strength reductions in the future. The major issue has held us back from making this change in the past is that taking an MVCC snapshot is significantly more expensive than using a static special snapshot such as SnapshotNow. However, testing of various worst-case scenarios reveals that this problem is not severe except under fairly extreme workloads. To mitigate those problems, we avoid retaking the MVCC snapshot for each new scan; instead, we take a new snapshot only when invalidation messages have been processed. The catcache machinery already requires that invalidation messages be sent before releasing the related heavyweight lock; else other backends might rely on locally-cached data rather than scanning the catalog at all. Thus, making snapshot reuse dependent on the same guarantees shouldn't break anything that wasn't already subtly broken. Patch by me. Review by Michael Paquier and Andres Freund.
2013-06-03Put back allow_system_table_mods check in heap_create().Heikki Linnakangas
This reverts commit a475c6036752c26dca538632b68fd2cc592976b7. Erik Rijkers reported back in January 2013 that after the patch, if you do "pg_dump -t myschema.mytable" to dump a single table, and restore that in a database where myschema does not exist, the table is silently created in pg_catalog instead. That is because pg_dump uses "SET search_path=myschema, pg_catalog" to set schema the table is created in. While allow_system_table_mods is not a very elegant solution to this, we can't leave it as it is, so for now, revert it back to the way it was previously.
2013-05-29pgindent run for release 9.3Bruce Momjian
This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
2013-04-30Record data_checksum_version in control file.Simon Riggs
The value is not used anywhere in code, but will allow future changes to the checksum version should that become necessary in the future.
2013-03-22Allow I/O reliability checks using 16-bit checksumsSimon Riggs
Checksums are set immediately prior to flush out of shared buffers and checked when pages are read in again. Hint bit setting will require full page write when block is dirtied, which causes various infrastructure changes. Extensive comments, docs and README. WARNING message thrown if checksum fails on non-all zeroes page; ERROR thrown but can be disabled with ignore_checksum_failure = on. Feature enabled by an initdb option, since transition from option off to option on is long and complex and has not yet been implemented. Default is not to use checksums. Checksum used is WAL CRC-32 truncated to 16-bits. Simon Riggs, Jeff Davis, Greg Smith Wide input and assistance from many community members. Thank you.
2013-01-13Improve handling of ereport(ERROR) and elog(ERROR).Tom Lane
In commit 71450d7fd6c7cf7b3e38ac56e363bff6a681973c, we added code to inform suitably-intelligent compilers that ereport() doesn't return if the elevel is ERROR or higher. This patch extends that to elog(), and also fixes a double-evaluation hazard that the previous commit created in ereport(), as well as reducing the emitted code size. The elog() improvement requires the compiler to support __VA_ARGS__, which should be available in just about anything nowadays since it's required by C99. But our minimum language baseline is still C89, so add a configure test for that. The previous commit assumed that ereport's elevel could be evaluated twice, which isn't terribly safe --- there are already counterexamples in xlog.c. On compilers that have __builtin_constant_p, we can use that to protect the second test, since there's no possible optimization gain if the compiler doesn't know the value of elevel. Otherwise, use a local variable inside the macros to prevent double evaluation. The local-variable solution is inferior because (a) it leads to useless code being emitted when elevel isn't constant, and (b) it increases the optimization level needed for the compiler to recognize that subsequent code is unreachable. But it seems better than not teaching non-gcc compilers about unreachability at all. Lastly, if the compiler has __builtin_unreachable(), we can use that instead of abort(), resulting in a noticeable code savings since no function call is actually emitted. However, it seems wise to do this only in non-assert builds. In an assert build, continue to use abort(), so that the behavior will be predictable and debuggable if the "impossible" happens. These changes involve making the ereport and elog macros emit do-while statement blocks not just expressions, which forces small changes in a few call sites. Andres Freund, Tom Lane, Heikki Linnakangas
2013-01-02Fix IsUnderPostmaster/EXEC_BACKEND confusionAlvaro Herrera
2013-01-01Update copyrights for 2013Bruce Momjian
Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
2012-10-23Add context info to OAT_POST_CREATE security hookAlvaro Herrera
... and have sepgsql use it to determine whether to check permissions during certain operations. Indexes that are being created as a result of REINDEX, for instance, do not need to have their permissions checked; they were already checked when the index was created. Author: KaiGai Kohei, slightly revised by me
2012-10-12In our source code, make a copy of getopt's 'optarg' string arguments,Bruce Momjian
rather than just storing a pointer.
2012-10-11Refactor flex and bison make rulesPeter Eisentraut
Numerous flex and bison make rules have appeared in the source tree over time, and they are all virtually identical, so we can replace them by pattern rules with some variables for customization. Users of pgxs will also be able to benefit from this.
2012-08-30Split tuple struct defs from htup.h to htup_details.hAlvaro Herrera
This reduces unnecessary exposure of other headers through htup.h, which is very widely included by many files. I have chosen to move the function prototypes to the new file as well, because that means htup.h no longer needs to include tupdesc.h. In itself this doesn't have much effect in indirect inclusion of tupdesc.h throughout the tree, because it's also required by execnodes.h; but it's something to explore in the future, and it seemed best to do the htup.h change now while I'm busy with it.
2012-07-18Fix management of pendingOpsTable in auxiliary processes.Tom Lane
mdinit() was misusing IsBootstrapProcessingMode() to decide whether to create an fsync pending-operations table in the current process. This led to creating a table not only in the startup and checkpointer processes as intended, but also in the bgwriter process, not to mention other auxiliary processes such as walwriter and walreceiver. Creation of the table in the bgwriter is fatal, because it absorbs fsync requests that should have gone to the checkpointer; instead they just sit in bgwriter local memory and are never acted on. So writes performed by the bgwriter were not being fsync'd which could result in data loss after an OS crash. I think there is no live bug with respect to walwriter and walreceiver because those never perform any writes of shared buffers; but the potential is there for future breakage in those processes too. To fix, make AuxiliaryProcessMain() export the current process's AuxProcType as a global variable, and then make mdinit() test directly for the types of aux process that should have a pendingOpsTable. Having done that, we might as well also get rid of the random bool flags such as am_walreceiver that some of the aux processes had grown. (Note that we could not have fixed the bug by examining those variables in mdinit(), because it's called from BaseInit() which is run by AuxiliaryProcessMain() before entering any of the process-type-specific code.) Back-patch to 9.2, where the problem was introduced by the split-up of bgwriter and checkpointer processes. The bogus pendingOpsTable exists in walwriter and walreceiver processes in earlier branches, but absent any evidence that it causes actual problems there, I'll leave the older branches alone.
2012-07-16Avoid pre-determining index names during CREATE TABLE LIKE parsing.Tom Lane
Formerly, when trying to copy both indexes and comments, CREATE TABLE LIKE had to pre-assign names to indexes that had comments, because it made up an explicit CommentStmt command to apply the comment and so it had to know the name for the index. This creates bad interactions with other indexes, as shown in bug #6734 from Daniele Varrazzo: the preassignment logic couldn't take any other indexes into account so it could choose a conflicting name. To fix, add a field to IndexStmt that allows it to carry a comment to be assigned to the new index. (This isn't a user-exposed feature of CREATE INDEX, only an internal option.) Now we don't need preassignment of index names in any situation. I also took the opportunity to refactor DefineIndex to accept the IndexStmt as such, rather than passing all its fields individually in a mile-long parameter list. Back-patch to 9.2, but no further, because it seems too dangerous to change IndexStmt or DefineIndex's API in released branches. The bug exists back to 9.0 where CREATE TABLE LIKE grew the ability to copy comments, but given the lack of prior complaints we'll just let it go unfixed before 9.2.
2012-06-14Remove misplaced sanity check from heap_create().Robert Haas
Even when allow_system_table_mods is not set, we allow creation of any type of SQL object in pg_catalog, except for relations. And you can get relations into pg_catalog, too, by initially creating them in some other schema and then moving them with ALTER .. SET SCHEMA. So this restriction, which prevents relations (only) from being created in pg_catalog directly, is fairly pointless. If we need a safety mechanism for this, it should be placed further upstream, so that it affects all SQL objects uniformly, and picks up both CREATE and SET SCHEMA. For now, just rip it out, per discussion with Tom Lane.
2012-01-01Update copyright notices for year 2012.Bruce Momjian
2011-11-02Refactor xlog.c to create src/backend/postmaster/startup.cSimon Riggs
Startup process now has its own dedicated file, just like all other special/background processes. Reduces role and size of xlog.c
2011-11-01Split work of bgwriter between 2 processes: bgwriter and checkpointer.Simon Riggs
bgwriter is now a much less important process, responsible for page cleaning duties only. checkpointer is now responsible for checkpoints and so has a key role in shutdown. Later patches will correct doc references to the now old idea that bgwriter performs checkpoints. Has beneficial effect on performance at high write rates, but mainly refactoring to more easily allow changes for power reduction by simplifying previously tortuous code around required to allow page cleaning and checkpointing to time slice in the same process. Patch by me, Review by Dickson Guedes
2011-09-09Simplify handling of the timezone GUC by making initdb choose the default.Tom Lane
We were doing some amazingly complicated things in order to avoid running the very expensive identify_system_timezone() procedure during GUC initialization. But there is an obvious fix for that, which is to do it once during initdb and have initdb install the system-specific default into postgresql.conf, as it already does for most other GUC variables that need system-environment-dependent defaults. This means that the timezone (and log_timezone) settings no longer have any magic behavior in the server. Per discussion.