Extend ADMIN SHOW DDL docs

[dveeden]

What is changed, added or deleted? (Required)

• Remove EBNF that's not part of ADMIN SHOW DDL...
• Add column descriptions for ADMIN SHOW DDL output
• Change ADMIN SHOW DDL output to vertical to make it more readable
• Add some common JOB_TYPE's
• Add description for CREATE_TIME and END_TIME for the ADMIN SHOW DDL JOBS output.
• Add more links to the See also
• Fix EBNF to add LIMIT n,m in addition to LIMIT n OFFSET m. (Thanks @kennytm )

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• v5.1 (TiDB 5.1 versions)

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Do your changes match any of the following descriptions?

• Delete files
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• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

[dveeden]

For reference, output from ADMIN SHOW DDL with a running job. This is with unistore instead of TiKV, so I'm not 100% sure how representative this is.

mysql> admin show ddl\G
*************************** 1. row ***************************
   SCHEMA_VER: 5055
     OWNER_ID: eef31ae6-14a2-4664-85d7-dc842ccd62e4
OWNER_ADDRESS: 192.168.1.229:4000
 RUNNING_JOBS: ID:10106, Type:add index, State:running, SchemaState:write reorganization, SchemaID:2, TableID:10104, RowCount:1447630, ArgLen:0, start time: 2024-04-26 11:20:02.291 +0200 CEST, Err:<nil>, ErrCount:0, SnapshotVersion:449347112749760513, LocalMode: false, UniqueWarnings:0
      SELF_ID: eef31ae6-14a2-4664-85d7-dc842ccd62e4
        QUERY: alter table t1 add index (c1(100))
1 row in set (0.00 sec)

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[qiancai]

Rest LGTM

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-05-06 03:10:25.596451461 +0000 UTC m=+845179.353587035: ☑️ agreed by qiancai.

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[qiancai]

/approve

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