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Posted to issues@drill.apache.org by "Daniel Barclay (Drill) (JIRA)" <ji...@apache.org> on 2015/04/10 03:30:12 UTC
[jira] [Commented] (DRILL-2459) INFO._SCHEMA's
CHARACTER_MAXIMUM_LENGTH is -1 for type CHAR
[ https://issues.apache.org/jira/browse/DRILL-2459?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14488723#comment-14488723 ]
Daniel Barclay (Drill) commented on DRILL-2459:
-----------------------------------------------
Note: I already have draft code for a number of problems in INFORMATION_SCHEMA.COLUMNS.
(Maybe I should finish that and address this problem.)
> INFO._SCHEMA's CHARACTER_MAXIMUM_LENGTH is -1 for type CHAR
> -----------------------------------------------------------
>
> Key: DRILL-2459
> URL: https://issues.apache.org/jira/browse/DRILL-2459
> Project: Apache Drill
> Issue Type: Bug
> Components: Metadata
> Reporter: Daniel Barclay (Drill)
> Assignee: Daniel Barclay (Drill)
> Fix For: 1.0.0
>
>
> INFORMATION_SCHEMA.COLUMNS.CHARACTER_MAXIMUM_LENGTH does not report the length for type CHAR. For example, for type descriptor "CHAR(4)", it doesn't return 4. Instead, it returns -1:
> 0: jdbc:drill:zk=local> USE dfs.tmp;
> +------------+------------+
> | ok | summary |
> +------------+------------+
> | true | Default schema changed to 'dfs.tmp' |
> +------------+------------+
> 1 row selected (0.05 seconds)
> 0: jdbc:drill:zk=local> CREATE OR REPLACE VIEW TempView AS SELECT CAST( NULL AS VARCHAR(3) ), CAST( NULL AS CHAR(4) ) FROM INFORMATION_SCHEMA.CATALOGS LIMIT 1 ;
> +------------+------------+
> | ok | summary |
> +------------+------------+
> | true | View 'TempView' replaced successfully in 'dfs.tmp' schema |
> +------------+------------+
> 1 row selected (0.05 seconds)
> 0: jdbc:drill:zk=local> SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'TempView';
> +---------------+--------------+------------+-------------+------------------+-------------+------------+--------------------------+-------------------------+---------------+-------------------+
> | TABLE_CATALOG | TABLE_SCHEMA | TABLE_NAME | COLUMN_NAME | ORDINAL_POSITION | IS_NULLABLE | DATA_TYPE | CHARACTER_MAXIMUM_LENGTH | NUMERIC_PRECISION_RADIX | NUMERIC_SCALE | NUMERIC_PRECISION |
> +---------------+--------------+------------+-------------+------------------+-------------+------------+--------------------------+-------------------------+---------------+-------------------+
> | DRILL | dfs.tmp | TempView | EXPR$0 | 0 | NO | VARCHAR | 3 | -1 | -1 | -1 |
> | DRILL | dfs.tmp | TempView | EXPR$1 | 1 | NO | CHAR | -1 | -1 | -1 | 4 |
> +---------------+--------------+------------+-------------+------------------+-------------+------------+--------------------------+-------------------------+---------------+-------------------+
> 2 rows selected (0.072 seconds)
> 0: jdbc:drill:zk=local>
> Hmm. Note the 4 in the NUMERIC_PRECISION column:
> 0: jdbc:drill:zk=local> SELECT DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'TempView';
> +------------+--------------------------+-------------------+
> | DATA_TYPE | CHARACTER_MAXIMUM_LENGTH | NUMERIC_PRECISION |
> +------------+--------------------------+-------------------+
> | VARCHAR | 3 | -1 |
> | CHAR | -1 | 4 |
> +------------+--------------------------+-------------------+
> 2 rows selected (0.065 seconds)
> 0: jdbc:drill:zk=local>
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