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  1. MariaDB Server
  2. MDEV-20263

sql_mode=ORACLE: BLOB(65535) should not translate to LONGBLOB

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Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 10.3, 10.4, 10.5
    • 10.3.18, 10.4.8
    • Data types
    • None

    Description

      Oracle database has the following syntax for the BLOB data type:

      { BLOB | BINARY LARGE OBJECT } [ ( length [{K |M |G }] ) ]
      

      The default BLOB length is two gigabytes (2,147,483,647).

      To satisfy the default length of 2Gb, when running with sql_mode=ORACLE, MariaDB translates:

      CREATE TABLE t1 (a BLOB);
      

      to

      CREATE TABLE t1 (a LONGBLOB);
      

      But it also translates:

      CREATE TABLE t1 (a BLOB(65535));
      

      to

      CREATE TABLE t1 (a LONGBLOB);
      

      The latter looks wrong. When explicit length is specified, it should try to preserve the BLOB data type, corresponding to MYSQL_TYPE_BLOB (which uses 2 bytes per length).

      This script demonstrates the problem:

      SET sql_mode=ORACLE;
      CREATE OR REPLACE TABLE t1 (a BLOB(65535));
      SHOW CREATE TABLE t1;
      

      +-------+---------------------------------------------------+
      | Table | Create Table                                      |
      +-------+---------------------------------------------------+
      | t1    | CREATE TABLE "t1" (
        "a" longblob DEFAULT NULL
      ) |
      +-------+---------------------------------------------------+
      

      The expected output in the last script (with sql_mode=ORACLE) should be:

      +-------+---------------------------------------------------+
      | Table | Create Table                                      |
      +-------+---------------------------------------------------+
      | t1    | CREATE TABLE "t1" (
        "a" blob(65535) DEFAULT NULL
      ) |
      +-------+---------------------------------------------------+
      

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              bar Alexander Barkov
              bar Alexander Barkov
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              Dates

                Created:
                Updated:
                Resolved:

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