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https://github.com/mariadb-corporation/mariadb-columnstore-engine.git
synced 2025-04-28 06:45:06 +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.
29 lines
765 B
Plaintext
29 lines
765 B
Plaintext
#
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# LEFT() function
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# Author: Bharath, bharath.bokka@mariadb.com
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#
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-- source ../include/have_columnstore.inc
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--disable_warnings
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DROP DATABASE IF EXISTS mcs286_db;
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--enable_warnings
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CREATE DATABASE mcs286_db;
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USE mcs286_db;
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CREATE TABLE t1 (a INT, b CHAR(15))ENGINE=Columnstore;
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INSERT INTO t1 VALUES (NULL, NULL),(1, 'mariadb'),(2, 'columnstore'),(3, 'Innodb');
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SELECT LEFT('mariadb cs', 7) FROM t1 LIMIT 1;
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SELECT LEFT('mariadb cs', 8) FROM t1 LIMIT 1;
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SELECT LEFT('mariadb cs', 9) FROM t1 LIMIT 1;
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SELECT b, LEFT(b, 0) FROM t1 ORDER BY 1;
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SELECT b, LEFT(b, -1) FROM t1 ORDER BY 1;
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SELECT b, LEFT(b, 6) FROM t1 ORDER BY 1;
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SELECT b, LEFT(b, 9) FROM t1 ORDER BY 1;
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SELECT b, LEFT(concat('mmm_', b), 10) FROM t1 ORDER BY 1;
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# Clean UP
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DROP DATABASE mcs286_db;
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