Thread: pgsql: Create a "relation mapping" infrastructure to support changing
pgsql: Create a "relation mapping" infrastructure to support changing
From
tgl@postgresql.org (Tom Lane)
Date:
Log Message: ----------- Create a "relation mapping" infrastructure to support changing the relfilenodes of shared or nailed system catalogs. This has two key benefits: * The new CLUSTER-based VACUUM FULL can be applied safely to all catalogs. * We no longer have to use an unsafe reindex-in-place approach for reindexing shared catalogs. CLUSTER on nailed catalogs now works too, although I left it disabled on shared catalogs because the resulting pg_index.indisclustered update would only be visible in one database. Since reindexing shared system catalogs is now fully transactional and crash-safe, the former special cases in REINDEX behavior have been removed; shared catalogs are treated the same as non-shared. This commit does not do anything about the recently-discussed problem of deadlocks between VACUUM FULL/CLUSTER on a system catalog and other concurrent queries; will address that in a separate patch. As a stopgap, parallel_schedule has been tweaked to run vacuum.sql by itself, to avoid such failures during the regression tests. Modified Files: -------------- pgsql/contrib/oid2name: oid2name.c (r1.36 -> r1.37) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/contrib/oid2name/oid2name.c?r1=1.36&r2=1.37) pgsql/doc/src/sgml: catalogs.sgml (r2.220 -> r2.221) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml?r1=2.220&r2=2.221) diskusage.sgml (r1.19 -> r1.20) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/diskusage.sgml?r1=1.19&r2=1.20) func.sgml (r1.500 -> r1.501) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.500&r2=1.501) pgbuffercache.sgml (r2.5 -> r2.6) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/pgbuffercache.sgml?r1=2.5&r2=2.6) storage.sgml (r1.30 -> r1.31) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/storage.sgml?r1=1.30&r2=1.31) pgsql/doc/src/sgml/ref: cluster.sgml (r1.47 -> r1.48) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/cluster.sgml?r1=1.47&r2=1.48) reindex.sgml (r1.38 -> r1.39) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/reindex.sgml?r1=1.38&r2=1.39) pgsql/src/backend/access/index: genam.c (r1.79 -> r1.80) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/index/genam.c?r1=1.79&r2=1.80) pgsql/src/backend/access/transam: rmgr.c (r1.28 -> r1.29) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/rmgr.c?r1=1.28&r2=1.29) xact.c (r1.282 -> r1.283) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.282&r2=1.283) xlog.c (r1.366 -> r1.367) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlog.c?r1=1.366&r2=1.367) pgsql/src/backend/bootstrap: bootparse.y (r1.104 -> r1.105) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootparse.y?r1=1.104&r2=1.105) bootstrap.c (r1.258 -> r1.259) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootstrap.c?r1=1.258&r2=1.259) pgsql/src/backend/catalog: catalog.c (r1.87 -> r1.88) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/catalog.c?r1=1.87&r2=1.88) heap.c (r1.369 -> r1.370) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/heap.c?r1=1.369&r2=1.370) index.c (r1.332 -> r1.333) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/index.c?r1=1.332&r2=1.333) storage.c (r1.7 -> r1.8) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/storage.c?r1=1.7&r2=1.8) toasting.c (r1.29 -> r1.30) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/toasting.c?r1=1.29&r2=1.30) pgsql/src/backend/commands: cluster.c (r1.197 -> r1.198) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/cluster.c?r1=1.197&r2=1.198) indexcmds.c (r1.190 -> r1.191) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/indexcmds.c?r1=1.190&r2=1.191) tablecmds.c (r1.324 -> r1.325) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c?r1=1.324&r2=1.325) vacuum.c (r1.403 -> r1.404) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuum.c?r1=1.403&r2=1.404) pgsql/src/backend/executor: execMain.c (r1.344 -> r1.345) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execMain.c?r1=1.344&r2=1.345) pgsql/src/backend/parser: parse_clause.c (r1.195 -> r1.196) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/parse_clause.c?r1=1.195&r2=1.196) pgsql/src/backend/utils/adt: dbsize.c (r1.28 -> r1.29) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/dbsize.c?r1=1.28&r2=1.29) pgsql/src/backend/utils/cache: Makefile (r1.25 -> r1.26) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/Makefile?r1=1.25&r2=1.26) catcache.c (r1.148 -> r1.149) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/catcache.c?r1=1.148&r2=1.149) inval.c (r1.93 -> r1.94) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/inval.c?r1=1.93&r2=1.94) relcache.c (r1.302 -> r1.303) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/relcache.c?r1=1.302&r2=1.303) pgsql/src/backend/utils/init: miscinit.c (r1.180 -> r1.181) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/miscinit.c?r1=1.180&r2=1.181) pgsql/src/bin/pg_dump: pg_dump.c (r1.569 -> r1.570) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c?r1=1.569&r2=1.570) pgsql/src/include/access: rmgr.h (r1.20 -> r1.21) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/access/rmgr.h?r1=1.20&r2=1.21) pgsql/src/include/catalog: catalog.h (r1.47 -> r1.48) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catalog.h?r1=1.47&r2=1.48) catversion.h (r1.582 -> r1.583) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.582&r2=1.583) heap.h (r1.96 -> r1.97) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/heap.h?r1=1.96&r2=1.97) index.h (r1.81 -> r1.82) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/index.h?r1=1.81&r2=1.82) pg_class.h (r1.120 -> r1.121) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_class.h?r1=1.120&r2=1.121) pg_proc.h (r1.567 -> r1.568) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.567&r2=1.568) storage.h (r1.4 -> r1.5) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/storage.h?r1=1.4&r2=1.5) pgsql/src/include/commands: cluster.h (r1.39 -> r1.40) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/cluster.h?r1=1.39&r2=1.40) pgsql/src/include: miscadmin.h (r1.217 -> r1.218) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/miscadmin.h?r1=1.217&r2=1.218) pgsql/src/include/storage: lwlock.h (r1.43 -> r1.44) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/lwlock.h?r1=1.43&r2=1.44) relfilenode.h (r1.24 -> r1.25) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/relfilenode.h?r1=1.24&r2=1.25) sinval.h (r1.56 -> r1.57) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/sinval.h?r1=1.56&r2=1.57) pgsql/src/include/utils: builtins.h (r1.346 -> r1.347) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/builtins.h?r1=1.346&r2=1.347) catcache.h (r1.69 -> r1.70) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/catcache.h?r1=1.69&r2=1.70) inval.h (r1.47 -> r1.48) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/inval.h?r1=1.47&r2=1.48) rel.h (r1.121 -> r1.122) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/rel.h?r1=1.121&r2=1.122) relcache.h (r1.67 -> r1.68) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/relcache.h?r1=1.67&r2=1.68) pgsql/src/test/regress/expected: vacuum.out (r1.3 -> r1.4) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/vacuum.out?r1=1.3&r2=1.4) pgsql/src/test/regress: parallel_schedule (r1.58 -> r1.59) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/parallel_schedule?r1=1.58&r2=1.59) Added Files: ----------- pgsql/src/backend/utils/cache: relmapper.c (r1.1) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/relmapper.c?rev=1.1&content-type=text/x-cvsweb-markup) pgsql/src/include/utils: relmapper.h (r1.1) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/relmapper.h?rev=1.1&content-type=text/x-cvsweb-markup)
On Sun, 2010-02-07 at 20:48 +0000, Tom Lane wrote: > Log Message: > ----------- > Create a "relation mapping" infrastructure to support changing the relfilenodes > of shared or nailed system catalogs. This has two key benefits: > > * The new CLUSTER-based VACUUM FULL can be applied safely to all catalogs. > > * We no longer have to use an unsafe reindex-in-place approach for reindexing > shared catalogs. > > CLUSTER on nailed catalogs now works too, although I left it disabled on > shared catalogs because the resulting pg_index.indisclustered update would > only be visible in one database. > > Since reindexing shared system catalogs is now fully transactional and > crash-safe, the former special cases in REINDEX behavior have been removed; > shared catalogs are treated the same as non-shared. > > This commit does not do anything about the recently-discussed problem of > deadlocks between VACUUM FULL/CLUSTER on a system catalog and other > concurrent queries; will address that in a separate patch. As a stopgap, > parallel_schedule has been tweaked to run vacuum.sql by itself, to avoid > such failures during the regression tests. Awesome! Few questions: We XLogFlush() in normal running, but not in recovery. Would it be possible for the map changes to hit disk after the data changes in that case? What we're saying is if we process a relmap update WAL record then it doesn't really matter whether or not we commit that transaction? > func.sgml (r1.500 -> r1.501) > (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.500&r2=1.501) It would be useful to mention that the return value is volatile and can change across transactions or even within a transaction, just like ctid. > catalogs.sgml (r2.220 -> r2.221) > (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml?r1=2.220&r2=2.221) No mention of pg_relation_filepath/filenode in there. -- Simon Riggs www.2ndQuadrant.com
Simon Riggs <simon@2ndquadrant.com> writes: > Few questions: > We XLogFlush() in normal running, but not in recovery. Would it be > possible for the map changes to hit disk after the data changes in that > case? No, because the map change is flushed to disk on sight of the WAL record anyway. > What we're saying is if we process a relmap update WAL record then it > doesn't really matter whether or not we commit that transaction? Right. relmap update is committed independently of the surrounding transaction. > It would be useful to mention that the return value is volatile and can > change across transactions or even within a transaction, just like ctid. Hm. I thought it was more reasonable to treat it as "stable", which is the normal case. You're right that there are some corner cases where it could change without the caller's snapshot changing, but I'm not sure it's worth worrying about. regards, tom lane
On Sun, 2010-02-07 at 17:52 -0500, Tom Lane wrote: > > > It would be useful to mention that the return value is volatile and > can change across transactions or even within a transaction, just like > ctid. > > Hm. I thought it was more reasonable to treat it as "stable", which > is the normal case. You're right that there are some corner cases > where it could change without the caller's snapshot changing, but I'm > not sure it's worth worrying about. OK, even if its stable I think we need to mention it because it's not obvious that the file we keep catalog data in could change name. It's a also a change from earlier releases where that would never happen. -- Simon Riggs www.2ndQuadrant.com