4 Commits (1b9050da66aba821fec18376bee30d17e91e7027)

Author	SHA1	Message	Date
John Naylor	1b9050da66	Remove empty statement ... Peter Smith Discussion: https://www.postgresql.org/message-id/CAHut%2BPtRGVuj8Q_GpHHxZyk7fGwdYDG8_s4GSfKoc_4Yd9vR-w%40mail.gmail.com	3 years ago
Robert Haas	b0a55e4329	Change internal RelFileNode references to RelFileNumber or RelFileLocator. ... We have been using the term RelFileNode to refer to either (1) the integer that is used to name the sequence of files for a certain relation within the directory set aside for that tablespace/database combination; or (2) that value plus the OIDs of the tablespace and database; or occasionally (3) the whole series of files created for a relation based on those values. Using the same name for more than one thing is confusing. Replace RelFileNode with RelFileNumber when we're talking about just the single number, i.e. (1) from above, and with RelFileLocator when we're talking about all the things that are needed to locate a relation's files on disk, i.e. (2) from above. In the places where we refer to (3) as a relfilenode, instead refer to "relation storage". Since there is a ton of SQL code in the world that knows about pg_class.relfilenode, don't change the name of that column, or of other SQL-facing things that derive their name from it. On the other hand, do adjust closely-related internal terminology. For example, the structure member names dbNode and spcNode appear to be derived from the fact that the structure itself was called RelFileNode, so change those to dbOid and spcOid. Likewise, various variables with names like rnode and relnode get renamed appropriately, according to how they're being used in context. Hopefully, this is clearer than before. It is also preparation for future patches that intend to widen the relfilenumber fields from its current width of 32 bits. Variables that store a relfilenumber are now declared as type RelFileNumber rather than type Oid; right now, these are the same, but that can now more easily be changed. Dilip Kumar, per an idea from me. Reviewed also by Andres Freund. I fixed some whitespace issues, changed a couple of words in a comment, and made one other minor correction. Discussion: http://postgr.es/m/CA+TgmoamOtXbVAQf9hWFzonUo6bhhjS6toZQd7HZ-pmojtAmag@mail.gmail.com Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com Discussion: http://postgr.es/m/CAFiTN-vTe79M8uDH1yprOU64MNFE+R3ODRuA+JWf27JbhY4hJw@mail.gmail.com	3 years ago
Thomas Munro	acf1dd4234	Don't retry restore_command while reading ahead. ... Suppress further attempts to read ahead in the WAL if we run out of data, until the records already decoded have been replayed. This restores the traditional behavior for continuous archive recovery, which is to retry the failing restore_command only every 5 seconds. With the coding in 5dc0418f, we would start retrying every time through the recovery loop when our WAL decoding window hit the end of the current segment and we tried to look ahead into a not-yet-available next file. That was very slow. Also change the no_readahead_until mechanism to use <= rather than <, which seems more useful. Otherwise we'd either get one extra unwanted retry of restore_command, or we'd need to add 1 to an LSN. No change in behavior for regular streaming. That was already limited by the flushedUpto variable, which won't be updated until we replay what we have already. Reported by Andres Freund while analyzing the failure of a TAP test on build farm animal skink (investigation ongoing but probably due to otherwise unrelated timing bugs triggered by this slowness magnified by valgrind). Discussion: https://postgr.es/m/20220409005910.alw46xqmmgny2sgr%40alap3.anarazel.de	3 years ago
Thomas Munro	5dc0418fab	Prefetch data referenced by the WAL, take II. ... Introduce a new GUC recovery_prefetch. When enabled, look ahead in the WAL and try to initiate asynchronous reading of referenced data blocks that are not yet cached in our buffer pool. For now, this is done with posix_fadvise(), which has several caveats. Since not all OSes have that system call, "try" is provided so that it can be enabled where available. Better mechanisms for asynchronous I/O are possible in later work. Set to "try" for now for test coverage. Default setting to be finalized before release. The GUC wal_decode_buffer_size limits the distance we can look ahead in bytes of decoded data. The existing GUC maintenance_io_concurrency is used to limit the number of concurrent I/Os allowed, based on pessimistic heuristics used to infer that I/Os have begun and completed. We'll also not look more than maintenance_io_concurrency * 4 block references ahead. Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> (earlier version) Reviewed-by: Andres Freund <andres@anarazel.de> (earlier version) Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> (earlier version) Tested-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> (earlier version) Tested-by: Jakub Wartak <Jakub.Wartak@tomtom.com> (earlier version) Tested-by: Dmitry Dolgov <9erthalion6@gmail.com> (earlier version) Tested-by: Sait Talha Nisanci <Sait.Nisanci@microsoft.com> (earlier version) Discussion: https://postgr.es/m/CA%2BhUKGJ4VJN8ttxScUFM8dOKX0BrBiboo5uz1cq%3DAovOddfHpA%40mail.gmail.com	3 years ago