/ Ticket Change Details
Login
SQLite training in Houston TX on 2019-11-05 (details)
Part of the 2019 Tcl Conference
Overview

Artifact ID: 2db52790f128645fcedc8010cfe726f15da57c08
Ticket: f68bf68513a1c15ff405c54e39e637a9f8156f7b
ALTER TABLE corrupts DESC indexes
User & Date: drh 2016-07-14 18:46:40
Changes

  1. Change foundin to "3.13.0"
  2. Change icomment to:

    The change to ALTER TABLE in [e1d8ec85546c] can cause indexes to go corrupt. Sample code:

    PRAGMA legacy_file_format=ON;
    CREATE TABLE t1(a,b,c);
    CREATE INDEX t1a ON t1(a DESC);
    INSERT INTO t1 VALUES(1,2,3);
    INSERT INTO t1 VALUES(2,3,4);
    ALTER TABLE t1 ADD COLUMN d;
    PRAGMA integrity_check;
    

    If the schema version is initially less than 4, then the DESC keyword on indexes is ignored. If ALTER TABLE then changes the schema version to 4 from a smaller value, then preexisting DESC indexes will be in the wrong order.

    Corruption caused by this bug can be fixed by running the REINDEX command.

  3. Change login to "drh"
  4. Change mimetype to "text/x-fossil-wiki"
  5. Change severity to "Severe"
  6. Change status to "Open"
  7. Change title to "ALTER TABLE corrupts DESC indexes"
  8. Change type to "Code_Defect"