database/mariadb-columnstore-engine
1
0
Fork 0
mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-07-30 19:23:07 +03:00
Code Activity

MCOL-271 empty strings should not be NULLs (#2794)

Browse Source 
This patch improves handling of NULLs in textual fields in ColumnStore.
Previously empty strings were considered NULLs and it could be a problem
if data scheme allows for empty strings. It was also one of major
reasons of behavior difference between ColumnStore and other engines in
MariaDB family.

Also, this patch fixes some other bugs and incorrect behavior, for
example, incorrect comparison for "column <= ''" which evaluates to
constant True for all purposes before this patch.
This commit is contained in:
Sergey Zefirov
2023-03-30 17:26:45 +01:00
committed by Roman Nozdrin
parent 0ea592da80
commit b53c231ca6
417 changed files with 12459 additions and 3520 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
mysql-test/columnstore/basic/r/mcs79_exists.result
View File

@ -8,8 +8,8 @@ CREATE TABLE t1 (t1_int INT, t1_char CHAR(5))ENGINE=Columnstore;
CREATE TABLE t2 (t2_int INT, t2_char CHAR(5))ENGINE=Columnstore;
CREATE TABLE t3 (t3_int INT, t3_char CHAR(5))ENGINE=Innodb;
CREATE TABLE t4 (t4_int INT, t4_char CHAR(5))ENGINE=Myisam;
INSERT INTO t1 VALUES (NULL, ''),(1, 'aaa'),(2, 'aaa'),(3, 'ccc'),(4, 'ddd'),(5, 'aaa'),(6, ''),(7, 'eee');
INSERT INTO t2 VALUES (NULL, ''),(1, 'eee'),(3, 'ccc'),(5, 'jjj'),(6, ''),(7, 'lll'),(9, 'eee'),(11, 'nnn');
INSERT INTO t1 VALUES (NULL, NULL),(1, 'aaa'),(2, 'aaa'),(3, 'ccc'),(4, 'ddd'),(5, 'aaa'),(6, ''),(7, 'eee');
INSERT INTO t2 VALUES (NULL, NULL),(1, 'eee'),(3, 'ccc'),(5, 'jjj'),(6, ''),(7, 'lll'),(9, 'eee'),(11, 'nnn');
INSERT INTO t3 SELECT * FROM t2;
INSERT INTO t4 SELECT * FROM t1;
SELECT t1_int FROM t1 WHERE EXISTS (SELECT t2_int FROM t2 WHERE t1.t1_int = t2.t2_int) ORDER BY 1;
@ -29,7 +29,7 @@ t2_int t2_char
1 eee
3 ccc
5 jjj
6 NULL
6
7 lll
SELECT t1_char FROM t1 WHERE NOT EXISTS (SELECT t2_int FROM t2 WHERE t1.t1_int = t2.t2_int) ORDER BY t1_char;
t1_char
@ -39,7 +39,7 @@ ddd
SELECT t1_char FROM t1 WHERE EXISTS (SELECT 1 FROM t2 WHERE t2_int IS NULL) ORDER BY 1;
t1_char
NULL
NULL
aaa
aaa
aaa
@ -48,7 +48,7 @@ ddd
eee
SELECT t1_char, t1_int FROM t1 WHERE EXISTS (SELECT 1 FROM t2 WHERE t2_int IS NULL) AND t1_int > 5 ORDER BY 1;
t1_char t1_int
NULL 6
6
eee 7
SELECT t1_int FROM t1 WHERE EXISTS (SELECT t3_int FROM t3 WHERE t1.t1_int = t3.t3_int);
t1_int