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Commitb60acaf

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The following small patch provides a couple of minor updates (against
CVS HEAD):Amended "strings" regression test. TOAST tests now insert two valueswith storage set to "external", to exercise properly the TOAST sliceroutines which fetch only a subset of the chunks.Changed now-misleading comment on AlterTableCreateToastTable intablecmds.c, because both columns of the index on a toast table are nowused.John Gray
1 parent1923816 commitb60acaf

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3 files changed

+56
-13
lines changed

3 files changed

+56
-13
lines changed

‎src/backend/commands/tablecmds.c‎

Lines changed: 8 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.34 2002/08/27 03:56:34 momjian Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.35 2002/08/28 20:18:29 momjian Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -3417,12 +3417,13 @@ AlterTableCreateToastTable(Oid relOid, bool silent)
34173417
/*
34183418
* Create unique index on chunk_id, chunk_seq.
34193419
*
3420-
* NOTE: the tuple toaster could actually function with a single-column
3421-
* index on chunk_id only.However, it couldn't be unique then. We
3422-
* want it to be unique as a check against the possibility of
3423-
* duplicate TOAST chunk OIDs.Too, the index might be a little more
3424-
* efficient this way, since btree isn't all that happy with large
3425-
* numbers of equal keys.
3420+
* NOTE: the normal TOAST access routines could actually function with
3421+
* a single-column index on chunk_id only. However, the slice access
3422+
* routines use both columns for faster access to an individual chunk.
3423+
* In addition, we want it to be unique as a check against the
3424+
* possibility of duplicate TOAST chunk OIDs. The index might also be
3425+
* a little more efficient this way, since btree isn't all that happy
3426+
* with large numbers of equal keys.
34263427
*/
34273428

34283429
indexInfo=makeNode(IndexInfo);

‎src/test/regress/expected/strings.out‎

Lines changed: 32 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -579,14 +579,23 @@ SELECT text 'text' || varchar ' and varchar' AS "Concat text to varchar";
579579
CREATE TABLE toasttest(f1 text);
580580
insert into toasttest values(repeat('1234567890',10000));
581581
insert into toasttest values(repeat('1234567890',10000));
582+
--
583+
-- Ensure that some values are uncompressed, to test the faster substring
584+
-- operation used in that case
585+
--
586+
alter table toasttest alter column f1 set storage external;
587+
insert into toasttest values(repeat('1234567890',10000));
588+
insert into toasttest values(repeat('1234567890',10000));
582589
-- If the starting position is zero or less, then return from the start of the string
583590
-- adjusting the length to be consistent with the "negative start" per SQL92.
584591
SELECT substr(f1, -1, 5) from toasttest;
585592
substr
586593
--------
587594
123
588595
123
589-
(2 rows)
596+
123
597+
123
598+
(4 rows)
590599

591600
-- If the length is less than zero, an ERROR is thrown.
592601
SELECT substr(f1, 5, -1) from toasttest;
@@ -598,7 +607,9 @@ SELECT substr(f1, 99995) from toasttest;
598607
--------
599608
567890
600609
567890
601-
(2 rows)
610+
567890
611+
567890
612+
(4 rows)
602613

603614
-- If start plus length is > string length, the result is truncated to
604615
-- string length
@@ -607,7 +618,9 @@ SELECT substr(f1, 99995, 10) from toasttest;
607618
--------
608619
567890
609620
567890
610-
(2 rows)
621+
567890
622+
567890
623+
(4 rows)
611624

612625
DROP TABLE toasttest;
613626
--
@@ -616,14 +629,23 @@ DROP TABLE toasttest;
616629
CREATE TABLE toasttest(f1 bytea);
617630
insert into toasttest values(decode(repeat('1234567890',10000),'escape'));
618631
insert into toasttest values(decode(repeat('1234567890',10000),'escape'));
632+
--
633+
-- Ensure that some values are uncompressed, to test the faster substring
634+
-- operation used in that case
635+
--
636+
alter table toasttest alter column f1 set storage external;
637+
insert into toasttest values(decode(repeat('1234567890',10000),'escape'));
638+
insert into toasttest values(decode(repeat('1234567890',10000),'escape'));
619639
-- If the starting position is zero or less, then return from the start of the string
620640
-- adjusting the length to be consistent with the "negative start" per SQL92.
621641
SELECT substr(f1, -1, 5) from toasttest;
622642
substr
623643
--------
624644
123
625645
123
626-
(2 rows)
646+
123
647+
123
648+
(4 rows)
627649

628650
-- If the length is less than zero, an ERROR is thrown.
629651
SELECT substr(f1, 5, -1) from toasttest;
@@ -635,7 +657,9 @@ SELECT substr(f1, 99995) from toasttest;
635657
--------
636658
567890
637659
567890
638-
(2 rows)
660+
567890
661+
567890
662+
(4 rows)
639663

640664
-- If start plus length is > string length, the result is truncated to
641665
-- string length
@@ -644,7 +668,9 @@ SELECT substr(f1, 99995, 10) from toasttest;
644668
--------
645669
567890
646670
567890
647-
(2 rows)
671+
567890
672+
567890
673+
(4 rows)
648674

649675
DROP TABLE toasttest;
650676
--

‎src/test/regress/sql/strings.sql‎

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -206,6 +206,14 @@ CREATE TABLE toasttest(f1 text);
206206
insert into toasttestvalues(repeat('1234567890',10000));
207207
insert into toasttestvalues(repeat('1234567890',10000));
208208

209+
--
210+
-- Ensure that some values are uncompressed, to test the faster substring
211+
-- operation used in that case
212+
--
213+
altertable toasttest alter column f1set storage external;
214+
insert into toasttestvalues(repeat('1234567890',10000));
215+
insert into toasttestvalues(repeat('1234567890',10000));
216+
209217
-- If the starting position is zero or less, then return from the start of the string
210218
-- adjusting the length to be consistent with the "negative start" per SQL92.
211219
SELECT substr(f1,-1,5)from toasttest;
@@ -231,6 +239,14 @@ CREATE TABLE toasttest(f1 bytea);
231239
insert into toasttestvalues(decode(repeat('1234567890',10000),'escape'));
232240
insert into toasttestvalues(decode(repeat('1234567890',10000),'escape'));
233241

242+
--
243+
-- Ensure that some values are uncompressed, to test the faster substring
244+
-- operation used in that case
245+
--
246+
altertable toasttest alter column f1set storage external;
247+
insert into toasttestvalues(decode(repeat('1234567890',10000),'escape'));
248+
insert into toasttestvalues(decode(repeat('1234567890',10000),'escape'));
249+
234250
-- If the starting position is zero or less, then return from the start of the string
235251
-- adjusting the length to be consistent with the "negative start" per SQL92.
236252
SELECT substr(f1,-1,5)from toasttest;

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