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postgresql/src/include/access/gin.h

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GIN: Generalized Inverted iNdex. text[], int4[], Tsearch2 support for GIN.
2006-05-02 13:28:56 +02:00
/*--------------------------------------------------------------------------
* gin.h
Fix GIN to support null keys, empty and null items, and full index scans. Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
2011-01-08 01:16:24 +01:00
* Public header file for Generalized Inverted Index access method.
GIN: Generalized Inverted iNdex. text[], int4[], Tsearch2 support for GIN.
2006-05-02 13:28:56 +02:00
*
Update copyright for 2024 Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
2024-01-04 02:49:05 +01:00
* Copyright (c) 2006-2024, PostgreSQL Global Development Group
Tsearch2 functionality migrates to core. The bulk of this work is by Oleg Bartunov and Teodor Sigaev, but I did a lot of editorializing, so anything that's broken is probably my fault. Documentation is nonexistent as yet, but let's land the patch so we can get some portability testing done.
2007-08-21 03:11:32 +02:00
*
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/access/gin.h
GIN: Generalized Inverted iNdex. text[], int4[], Tsearch2 support for GIN.
2006-05-02 13:28:56 +02:00
*--------------------------------------------------------------------------
*/
#ifndef GIN_H
#define GIN_H
Revamp the WAL record format. Each WAL record now carries information about the modified relation and block(s) in a standardized format. That makes it easier to write tools that need that information, like pg_rewind, prefetching the blocks to speed up recovery, etc. There's a whole new API for building WAL records, replacing the XLogRecData chains used previously. The new API consists of XLogRegister* functions, which are called for each buffer and chunk of data that is added to the record. The new API also gives more control over when a full-page image is written, by passing flags to the XLogRegisterBuffer function. This also simplifies the XLogReadBufferForRedo() calls. The function can dig the relation and block number from the WAL record, so they no longer need to be passed as arguments. For the convenience of redo routines, XLogReader now disects each WAL record after reading it, copying the main data part and the per-block data into MAXALIGNed buffers. The data chunks are not aligned within the WAL record, but the redo routines can assume that the pointers returned by XLogRecGet* functions are. Redo routines are now passed the XLogReaderState, which contains the record in the already-disected format, instead of the plain XLogRecord. The new record format also makes the fixed size XLogRecord header smaller, by removing the xl_len field. The length of the "main data" portion is now stored at the end of the WAL record, and there's a separate header after XLogRecord for it. The alignment padding at the end of XLogRecord is also removed. This compansates for the fact that the new format would otherwise be more bulky than the old format. Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera, Fujii Masao.
2014-11-20 16:56:26 +01:00
#include "access/xlogreader.h"
Move the backup-block logic from XLogInsert to a new file, xloginsert.c. xlog.c is huge, this makes it a little bit smaller, which is nice. Functions related to putting together the WAL record are in xloginsert.c, and the lower level stuff for managing WAL buffers and such are in xlog.c. Also move the definition of XLogRecord to a separate header file. This causes churn in the #includes of all the files that write WAL records, and redo routines, but it avoids pulling in xlog.h into most places. Reviewed by Michael Paquier, Alvaro Herrera, Andres Freund and Amit Kapila.
2014-11-06 12:52:08 +01:00
#include "lib/stringinfo.h"
Clean up the #include mess a little. walsender.h should depend on xlog.h, not vice versa. (Actually, the inclusion was circular until a couple hours ago, which was even sillier; but Bruce broke it in the expedient rather than logically correct direction.) Because of that poor decision, plus blind application of pgrminclude, we had a situation where half the system was depending on xlog.h to include such unrelated stuff as array.h and guc.h. Clean up the header inclusion, and manually revert a lot of what pgrminclude had done so things build again. This episode reinforces my feeling that pgrminclude should not be run without adult supervision. Inclusion changes in header files in particular need to be reviewed with great care. More generally, it'd be good if we had a clearer notion of module layering to dictate which headers can sanely include which others ... but that's a big task for another day.
2011-09-04 07:13:16 +02:00
#include "storage/block.h"
Fix GIN to support null keys, empty and null items, and full index scans. Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
2011-01-08 01:16:24 +01:00
#include "utils/relcache.h"
GIN: Generalized Inverted iNdex. text[], int4[], Tsearch2 support for GIN.
2006-05-02 13:28:56 +02:00
/*
* amproc indexes for inverted indexes.
*/
#define GIN_COMPARE_PROC 1
#define GIN_EXTRACTVALUE_PROC 2
#define GIN_EXTRACTQUERY_PROC 3
#define GIN_CONSISTENT_PROC 4
Extend GIN to support partial-match searches, and extend tsquery to support prefix matching using this facility. Teodor Sigaev and Oleg Bartunov
2008-05-16 18:31:02 +02:00
#define GIN_COMPARE_PARTIAL_PROC 5
Allow opclasses to provide tri-valued GIN consistent functions. With the GIN "fast scan" feature, GIN can skip items without fetching all the keys for them, if it can prove that they don't match regardless of those keys. So far, it has done the proving by calling the boolean consistent function with all combinations of TRUE/FALSE for the unfetched keys, but since that's O(n^2), it becomes unfeasible with more than a few keys. We can avoid calling consistent with all the combinations, if we can tell the operator class implementation directly which keys are unknown. This commit includes a triConsistent function for the built-in array and tsvector opclasses. Alexander Korotkov, with some changes by me.
2014-03-12 16:13:22 +01:00
#define GIN_TRICONSISTENT_PROC 6
Implement operator class parameters PostgreSQL provides set of template index access methods, where opclasses have much freedom in the semantics of indexing. These index AMs are GiST, GIN, SP-GiST and BRIN. There opclasses define representation of keys, operations on them and supported search strategies. So, it's natural that opclasses may be faced some tradeoffs, which require user-side decision. This commit implements opclass parameters allowing users to set some values, which tell opclass how to index the particular dataset. This commit doesn't introduce new storage in system catalog. Instead it uses pg_attribute.attoptions, which is used for table column storage options but unused for index attributes. In order to evade changing signature of each opclass support function, we implement unified way to pass options to opclass support functions. Options are set to fn_expr as the constant bytea expression. It's possible due to the fact that opclass support functions are executed outside of expressions, so fn_expr is unused for them. This commit comes with some examples of opclass options usage. We parametrize signature length in GiST. That applies to multiple opclasses: tsvector_ops, gist__intbig_ops, gist_ltree_ops, gist__ltree_ops, gist_trgm_ops and gist_hstore_ops. Also we parametrize maximum number of integer ranges for gist__int_ops. However, the main future usage of this feature is expected to be json, where users would be able to specify which way to index particular json parts. Catversion is bumped. Discussion: https://postgr.es/m/d22c3a18-31c7-1879-fc11-4c1ce2f5e5af%40postgrespro.ru Author: Nikita Glukhov, revised by me Reviwed-by: Nikolay Shaplov, Robert Haas, Tom Lane, Tomas Vondra, Alvaro Herrera
2020-03-30 18:17:11 +02:00
#define GIN_OPTIONS_PROC 7
#define GINNProcs 7
GIN: Generalized Inverted iNdex. text[], int4[], Tsearch2 support for GIN.
2006-05-02 13:28:56 +02:00
/*
Fix GIN to support null keys, empty and null items, and full index scans. Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
2011-01-08 01:16:24 +01:00
* searchMode settings for extractQueryFn.
GIN: Generalized Inverted iNdex. text[], int4[], Tsearch2 support for GIN.
2006-05-02 13:28:56 +02:00
*/
Fix GIN to support null keys, empty and null items, and full index scans. Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
2011-01-08 01:16:24 +01:00
#define GIN_SEARCH_MODE_DEFAULT 0
#define GIN_SEARCH_MODE_INCLUDE_EMPTY 1
#define GIN_SEARCH_MODE_ALL 2
#define GIN_SEARCH_MODE_EVERYTHING 3 /* for internal use only */
Implement "fastupdate" support for GIN indexes, in which we try to accumulate multiple index entries in a holding area before adding them to the main index structure. This helps because bulk insert is (usually) significantly faster than retail insert for GIN. This patch also removes GIN support for amgettuple-style index scans. The API defined for amgettuple is difficult to support with fastupdate, and the previously committed partial-match feature didn't really work with it either. We might eventually figure a way to put back amgettuple support, but it won't happen for 8.4. catversion bumped because of change in GIN's pg_am entry, and because the format of GIN indexes changed on-disk (there's a metapage now, and possibly a pending list). Teodor Sigaev
2009-03-24 21:17:18 +01:00
Improve GIN indexscan cost estimation. The better estimate requires more statistics than we previously stored: in particular, counts of "entry" versus "data" pages within the index, as well as knowledge of the number of distinct key values. We collect this information during initial index build and update it during VACUUM, storing the info in new fields on the index metapage. No initdb is required because these fields will read as zeroes in a pre-existing index, and the new gincostestimate code is coded to behave (reasonably) sanely if they are zeroes. Teodor Sigaev, reviewed by Jan Urbanski, Tom Lane, and Itagaki Takahiro.
2010-10-18 02:52:32 +02:00
/*
* GinStatsData represents stats data for planner use
*/
typedef struct GinStatsData
{
BlockNumber nPendingPages;
BlockNumber nTotalPages;
BlockNumber nEntryPages;
BlockNumber nDataPages;
int64 nEntries;
Fix GIN to support null keys, empty and null items, and full index scans. Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
2011-01-08 01:16:24 +01:00
int32 ginVersion;
Improve GIN indexscan cost estimation. The better estimate requires more statistics than we previously stored: in particular, counts of "entry" versus "data" pages within the index, as well as knowledge of the number of distinct key values. We collect this information during initial index build and update it during VACUUM, storing the info in new fields on the index metapage. No initdb is required because these fields will read as zeroes in a pre-existing index, and the new gincostestimate code is coded to behave (reasonably) sanely if they are zeroes. Teodor Sigaev, reviewed by Jan Urbanski, Tom Lane, and Itagaki Takahiro.
2010-10-18 02:52:32 +02:00
} GinStatsData;
Rename GinLogicValue to GinTernaryValue. It's more descriptive. Also, get rid of the enum, and use #defines instead, per Greg Stark's suggestion.
2014-03-31 09:26:38 +02:00
/*
* A ternary value used by tri-consistent functions.
*
Use stdbool.h if suitable Using the standard bool type provided by C allows some recent compilers and debuggers to give better diagnostics. Also, some extension code and third-party headers are increasingly pulling in stdbool.h, so it's probably saner if everyone uses the same definition. But PostgreSQL code is not prepared to handle bool of a size other than 1, so we keep our own old definition if we encounter a stdbool.h with a bool of a different size. (Among current build farm members, this only applies to old macOS versions on PowerPC.) To check that the used bool is of the right size, add a static assertions about size of GinTernaryValue vs bool. This is currently the only place that assumes that bool and char are of the same size. Discussion: https://www.postgresql.org/message-id/flat/3a0fe7e1-5ed1-414b-9230-53bbc0ed1f49@2ndquadrant.com
2018-03-23 01:42:25 +01:00
* This must be of the same size as a bool because some code will cast a
* pointer to a bool to a pointer to a GinTernaryValue.
Rename GinLogicValue to GinTernaryValue. It's more descriptive. Also, get rid of the enum, and use #defines instead, per Greg Stark's suggestion.
2014-03-31 09:26:38 +02:00
*/
typedef char GinTernaryValue;
Allow opclasses to provide tri-valued GIN consistent functions. With the GIN "fast scan" feature, GIN can skip items without fetching all the keys for them, if it can prove that they don't match regardless of those keys. So far, it has done the proving by calling the boolean consistent function with all combinations of TRUE/FALSE for the unfetched keys, but since that's O(n^2), it becomes unfeasible with more than a few keys. We can avoid calling consistent with all the combinations, if we can tell the operator class implementation directly which keys are unknown. This commit includes a triConsistent function for the built-in array and tsvector opclasses. Alexander Korotkov, with some changes by me.
2014-03-12 16:13:22 +01:00
Static assertions cleanup Because we added StaticAssertStmt() first before StaticAssertDecl(), some uses as well as the instructions in c.h are now a bit backwards from the "native" way static assertions are meant to be used in C. This updates the guidance and moves some static assertions to better places. Specifically, since the addition of StaticAssertDecl(), we can put static assertions at the file level. This moves a number of static assertions out of function bodies, where they might have been stuck out of necessity, to perhaps better places at the file level or in header files. Also, when the static assertion appears in a position where a declaration is allowed, then using StaticAssertDecl() is more native than StaticAssertStmt(). Reviewed-by: John Naylor <john.naylor@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/flat/941a04e7-dd6f-c0e4-8cdf-a33b3338cbda%40enterprisedb.com
2022-12-08 14:30:01 +01:00
StaticAssertDecl(sizeof(GinTernaryValue) == sizeof(bool),
"sizes of GinTernaryValue and bool are not equal");
Rename GinLogicValue to GinTernaryValue. It's more descriptive. Also, get rid of the enum, and use #defines instead, per Greg Stark's suggestion.
2014-03-31 09:26:38 +02:00
#define GIN_FALSE 0 /* item is not present / does not match */
#define GIN_TRUE 1 /* item is present / matches */
#define GIN_MAYBE 2 /* don't know if item is present / don't know
* if matches */
Allow opclasses to provide tri-valued GIN consistent functions. With the GIN "fast scan" feature, GIN can skip items without fetching all the keys for them, if it can prove that they don't match regardless of those keys. So far, it has done the proving by calling the boolean consistent function with all combinations of TRUE/FALSE for the unfetched keys, but since that's O(n^2), it becomes unfeasible with more than a few keys. We can avoid calling consistent with all the combinations, if we can tell the operator class implementation directly which keys are unknown. This commit includes a triConsistent function for the built-in array and tsvector opclasses. Alexander Korotkov, with some changes by me.
2014-03-12 16:13:22 +01:00
Convert *GetDatum() and DatumGet*() macros to inline functions The previous macro implementations just cast the argument to a target type but did not check whether the input type was appropriate. The function implementation can do better type checking of the input type. For the *GetDatumFast() macros, converting to an inline function doesn't work in the !USE_FLOAT8_BYVAL case, but we can use AssertVariableIsOfTypeMacro() to get a similar level of type checking. Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/8528fb7e-0aa2-6b54-85fb-0c0886dbd6ed%40enterprisedb.com
2022-09-27 20:47:07 +02:00
static inline GinTernaryValue
DatumGetGinTernaryValue(Datum X)
{
return (GinTernaryValue) X;
}
static inline Datum
GinTernaryValueGetDatum(GinTernaryValue X)
{
return (Datum) X;
}
Rename GinLogicValue to GinTernaryValue. It's more descriptive. Also, get rid of the enum, and use #defines instead, per Greg Stark's suggestion.
2014-03-31 09:26:38 +02:00
#define PG_RETURN_GIN_TERNARY_VALUE(x) return GinTernaryValueGetDatum(x)
Allow opclasses to provide tri-valued GIN consistent functions. With the GIN "fast scan" feature, GIN can skip items without fetching all the keys for them, if it can prove that they don't match regardless of those keys. So far, it has done the proving by calling the boolean consistent function with all combinations of TRUE/FALSE for the unfetched keys, but since that's O(n^2), it becomes unfeasible with more than a few keys. We can avoid calling consistent with all the combinations, if we can tell the operator class implementation directly which keys are unknown. This commit includes a triConsistent function for the built-in array and tsvector opclasses. Alexander Korotkov, with some changes by me.
2014-03-12 16:13:22 +01:00
Add GUC and storage parameter to set the maximum size of GIN pending list. Previously the maximum size of GIN pending list was controlled only by work_mem. But the reasonable value of work_mem and the reasonable size of the list are basically not the same, so it was not appropriate to control both of them by only one GUC, i.e., work_mem. This commit separates new GUC, pending_list_cleanup_size, from work_mem to allow users to control only the size of the list. Also this commit adds pending_list_cleanup_size as new storage parameter to allow users to specify the size of the list per index. This is useful, for example, when users want to increase the size of the list only for the GIN index which can be updated heavily, and decrease it otherwise. Reviewed by Etsuro Fujita.
2014-11-11 13:08:21 +01:00
/* GUC parameters */
Fix GIN to support null keys, empty and null items, and full index scans. Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
2011-01-08 01:16:24 +01:00
extern PGDLLIMPORT int GinFuzzySearchLimit;
Apply PGDLLIMPORT markings broadly. Up until now, we've had a policy of only marking certain variables in the PostgreSQL header files with PGDLLIMPORT, but now we've decided to mark them all. This means that extensions running on Windows should no longer operate at a disadvantage as compared to extensions running on Linux: if the variable is present in a header file, it should be accessible. Discussion: http://postgr.es/m/CA+TgmoYanc1_FSfimhgiWSqVyP5KKmh5NP2BWNwDhO8Pg2vGYQ@mail.gmail.com
2022-04-08 14:16:38 +02:00
extern PGDLLIMPORT int gin_pending_list_limit;
Fix GIN to support null keys, empty and null items, and full index scans. Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
2011-01-08 01:16:24 +01:00
/* ginutil.c */
Improve GIN indexscan cost estimation. The better estimate requires more statistics than we previously stored: in particular, counts of "entry" versus "data" pages within the index, as well as knowledge of the number of distinct key values. We collect this information during initial index build and update it during VACUUM, storing the info in new fields on the index metapage. No initdb is required because these fields will read as zeroes in a pre-existing index, and the new gincostestimate code is coded to behave (reasonably) sanely if they are zeroes. Teodor Sigaev, reviewed by Jan Urbanski, Tom Lane, and Itagaki Takahiro.
2010-10-18 02:52:32 +02:00
extern void ginGetStats(Relation index, GinStatsData *stats);
Generate less WAL during GiST, GIN and SP-GiST index build. Instead of WAL-logging every modification during the build separately, first build the index without any WAL-logging, and make a separate pass through the index at the end, to write all pages to the WAL. This significantly reduces the amount of WAL generated, and is usually also faster, despite the extra I/O needed for the extra scan through the index. WAL generated this way is also faster to replay. For GiST, the LSN-NSN interlock makes this a little tricky. All pages must be marked with a valid (i.e. non-zero) LSN, so that the parent-child LSN-NSN interlock works correctly. We now use magic value 1 for that during index build. Change the fake LSN counter to begin from 1000, so that 1 is safely smaller than any real or fake LSN. 2 would've been enough for our purposes, but let's reserve a bigger range, in case we need more special values in the future. Author: Anastasia Lubennikova, Andrey V. Lepikhov Reviewed-by: Heikki Linnakangas, Dmitry Dolgov
2019-04-03 16:03:15 +02:00
extern void ginUpdateStats(Relation index, const GinStatsData *stats,
bool is_build);
Improve GIN indexscan cost estimation. The better estimate requires more statistics than we previously stored: in particular, counts of "entry" versus "data" pages within the index, as well as knowledge of the number of distinct key values. We collect this information during initial index build and update it during VACUUM, storing the info in new fields on the index metapage. No initdb is required because these fields will read as zeroes in a pre-existing index, and the new gincostestimate code is coded to behave (reasonably) sanely if they are zeroes. Teodor Sigaev, reviewed by Jan Urbanski, Tom Lane, and Itagaki Takahiro.
2010-10-18 02:52:32 +02:00
Implement "fastupdate" support for GIN indexes, in which we try to accumulate multiple index entries in a holding area before adding them to the main index structure. This helps because bulk insert is (usually) significantly faster than retail insert for GIN. This patch also removes GIN support for amgettuple-style index scans. The API defined for amgettuple is difficult to support with fastupdate, and the previously committed partial-match feature didn't really work with it either. We might eventually figure a way to put back amgettuple support, but it won't happen for 8.4. catversion bumped because of change in GIN's pg_am entry, and because the format of GIN indexes changed on-disk (there's a metapage now, and possibly a pending list). Teodor Sigaev
2009-03-24 21:17:18 +01:00
#endif /* GIN_H */