From 1eb8e668b4f1f1e5b95b93df538f6be5364a6d8c Mon Sep 17 00:00:00 2001 From: teodor Date: Fri, 20 Oct 2006 10:38:29 +0000 Subject: [PATCH] Update to current state --- README.gevel | 99 ++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 89 insertions(+), 10 deletions(-) diff --git a/README.gevel b/README.gevel index 0d865d7..d4981b9 100644 --- a/README.gevel +++ b/README.gevel @@ -1,15 +1,96 @@ -for 8.1+ postgresql +Gevel contrib module provides several functions useful for analyzing GiST index. -select gist_tree(INDEXNAME); -select gist_tree(INDEXNAME,MAXLEVEL); -select gist_stat(INDEXNAME); +[Online version] of this document (http://www.sai.msu.su/~megera/oddmuse/index.cgi/Gevel) +Caution: This module was designed for developers of GiST based indices ! -example from gmake installcheck on rtree_gist: -select * from gist_print('pix') as t(level int, valid bool, a box); +Authors -# select * from gist_print('pix') as t(level int, valid bool, a box) where level < 2; - level | valid | a + * Oleg Bartunov , Moscow, Moscow University, Russia + * Teodor Sigaev , Moscow, Delta-Soft Ltd.,Russia + +License + +Stable version, included into PostgreSQL distribution, released under +BSD license. Development version, available from this site, released under +the GNU General Public License, version 2 (June 1991) + +Install gevel module (requires 8.1+ version): +% cd PGSQLSRC/contrib +% tar xzvf gevel.tar.gz +% make +% make install +% make installcheck +% psql regression < gevel.sql + + * gist_stat(INDEXNAME) - show some statistics about GiST tree + +regression=# select gist_stat('pix'); + Number of levels: 2 +Number of pages: 30 +Number of leaf pages: 29 +Number of tuples: 3129 +Number of leaf tuples: 3100 +Total size of tuples: 137676 bytes +Total size of leaf tuples: 136400 bytes +Total size of index: 245760 bytes + + * gist_tree(INDEXNAME[,MAXLEVEL]) - show GiST tree up to MAXLEVEL + +regression=# select gist_tree('pix',0); + 0(l:0) blk: 0 numTuple: 29 free: 6888b(15.63%) + +Designation (from left to right): + + o 0 - page number + o (l:0) - tree level + o blk: 0 - block number + o numTuple: 29 - the number of tuples + o free: 6888b - free space in bytes + o (15.63%) - occupied space in percents + + * gist_tree(INDEXNAME) - show full GiST tree + +regression=# select gist_tree('pix'); + 0(l:0) blk: 0 numTuple: 29 free: 6888b(15.63%) + 1(l:1) blk: 13 numTuple: 180 free: 244b(97.01%) + 2(l:1) blk: 11 numTuple: 175 free: 464b(94.32%) + 3(l:1) blk: 2 numTuple: 101 free: 3720b(54.43%) + 4(l:1) blk: 17 numTuple: 111 free: 3280b(59.82%) + 5(l:1) blk: 18 numTuple: 101 free: 3720b(54.43%) + 6(l:1) blk: 10 numTuple: 98 free: 3852b(52.82%) + 7(l:1) blk: 19 numTuple: 111 free: 3280b(59.82%) + 8(l:1) blk: 9 numTuple: 97 free: 3896b(52.28%) + 9(l:1) blk: 20 numTuple: 104 free: 3588b(56.05%) + 10(l:1) blk: 14 numTuple: 96 free: 3940b(51.74%) + 11(l:1) blk: 21 numTuple: 106 free: 3500b(57.13%) + 12(l:1) blk: 7 numTuple: 103 free: 3632b(55.51%) + 13(l:1) blk: 1 numTuple: 101 free: 3720b(54.43%) + 14(l:1) blk: 16 numTuple: 97 free: 3896b(52.28%) + 15(l:1) blk: 24 numTuple: 103 free: 3632b(55.51%) + 16(l:1) blk: 4 numTuple: 98 free: 3852b(52.82%) + 17(l:1) blk: 25 numTuple: 98 free: 3852b(52.82%) + 18(l:1) blk: 3 numTuple: 97 free: 3896b(52.28%) + 19(l:1) blk: 26 numTuple: 96 free: 3940b(51.74%) + 20(l:1) blk: 6 numTuple: 103 free: 3632b(55.51%) + 21(l:1) blk: 8 numTuple: 162 free: 1036b(87.31%) + 22(l:1) blk: 23 numTuple: 94 free: 4028b(50.66%) + 23(l:1) blk: 12 numTuple: 82 free: 4556b(44.19%) + 24(l:1) blk: 27 numTuple: 105 free: 3544b(56.59%) + 25(l:1) blk: 5 numTuple: 90 free: 4204b(48.51%) + 26(l:1) blk: 28 numTuple: 100 free: 3764b(53.90%) + 27(l:1) blk: 22 numTuple: 101 free: 3720b(54.43%) + 28(l:1) blk: 15 numTuple: 95 free: 3984b(51.20%) + 29(l:1) blk: 29 numTuple: 95 free: 3984b(51.20%) + + * gist_print(INDEXNAME) - prints objects stored in GiST tree, + works only if objects in index have textual representation + (type_out functions should be implemented for given object type). + It's known to work with R-tree GiST based index. + Note, in example below, objects are of type box. + +# select * from gist_print('pix') as t(level int, valid bool, a box) where level =1; + level | valid | a -------+-------+----------------------------- 1 | t | (37357,50073),(34242,357) 1 | t | (43499,49770),(40358,43) @@ -41,5 +122,3 @@ select * from gist_print('pix') as t(level int, valid bool, a box); 1 | t | (31179,50040),(28113,25556) 1 | t | (28048,49694),(25000,25000) (29 rows) - - -- 2.37.3