mirror of
https://github.com/mariadb-corporation/mariadb-columnstore-engine.git
synced 2025-04-18 21:44:02 +03:00
b53c231ca6
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.
77 lines
1.6 KiB
Plaintext
77 lines
1.6 KiB
Plaintext
DROP DATABASE IF EXISTS mcs219_db;
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CREATE DATABASE mcs219_db;
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USE mcs219_db;
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CREATE TABLE t1 (a INT, b CHAR(35))ENGINE=Columnstore;
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INSERT INTO t1 VALUES (NULL, NULL),(1, 'columnstore engine'),(2, 'mariadb database');
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SELECT b, MID(b,4,5) FROM t1;
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b MID(b,4,5)
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NULL NULL
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columnstore engine umnst
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mariadb database iadb
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SELECT b, MID(b,12,5) FROM t1;
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b MID(b,12,5)
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NULL NULL
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columnstore engine engi
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mariadb database abase
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SELECT b, MID(b,5,15) FROM t1;
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b MID(b,5,15)
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NULL NULL
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columnstore engine mnstore engine
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mariadb database adb database
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SELECT b, MID(b,12,15) FROM t1;
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b MID(b,12,15)
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NULL NULL
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columnstore engine engine
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mariadb database abase
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SELECT b, MID(b,1,1) FROM t1;
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b MID(b,1,1)
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NULL NULL
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columnstore engine c
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mariadb database m
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SELECT b, MID(b,1,2) FROM t1;
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b MID(b,1,2)
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NULL NULL
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columnstore engine co
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mariadb database ma
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SELECT b, MID(b,5,5) FROM t1;
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b MID(b,5,5)
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NULL NULL
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columnstore engine mnsto
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mariadb database adb d
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SELECT b, MID(b,-2,5) FROM t1;
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b MID(b,-2,5)
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NULL NULL
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columnstore engine ne
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mariadb database se
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SELECT b, MID(b,-5,15) FROM t1;
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b MID(b,-5,15)
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NULL NULL
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columnstore engine ngine
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mariadb database abase
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SELECT b, MID(b,-15,15) FROM t1;
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b MID(b,-15,15)
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NULL NULL
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columnstore engine umnstore engine
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mariadb database ariadb database
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SELECT b, MID(b,0,0) FROM t1;
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b MID(b,0,0)
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NULL NULL
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columnstore engine
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mariadb database
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SELECT b, MID(b,1,0) FROM t1;
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b MID(b,1,0)
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NULL NULL
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columnstore engine
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mariadb database
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SELECT b, MID(b,0,1) FROM t1;
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b MID(b,0,1)
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NULL NULL
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columnstore engine
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mariadb database
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SELECT b, MID(b,-1,0) FROM t1;
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b MID(b,-1,0)
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NULL NULL
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columnstore engine
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mariadb database
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DROP DATABASE mcs219_db;
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