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https://issues.apache.org/jira/browse/CALCITE-464?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Julian Hyde closed CALCITE-464.
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Closing now that 1.0.0-incubating has been released.
> Make parser accept configurable max length for SQL identifier
> -------------------------------------------------------------
>
> Key: CALCITE-464
> URL: https://issues.apache.org/jira/browse/CALCITE-464
> Project: Calcite
> Issue Type: Improvement
> Reporter: Jinfeng Ni
> Assignee: Julian Hyde
> Fix For: 1.0.0-incubating
>
>
> Calcite currently uses 128 as the maximum length for sql identifier. We
> would like to enhance the SQL parser, so that each system should be able to
> choose its own identifier max length.
> The following is the discussion copied from the dev mailing list:
> ===============================================================
> [Jinfeng]
> Calcite (formly Optiq) has set the maximum length for an SQL identifier to
> 128. This sounds quite reasonable for an ordinary sql identifier. However,
> for system like Drill which allows user to query a file directly, it's quite
> likely to run out of the allowed identifier length.
> Drill allows the use case of :
>
> select * from dfs.schema.`directory1/directory2/filename.json`;
> The directory plus the filename is parsed as a SQL identifer. Since many file
> system would allow file name up to 255 bytes [1], it's likely user could use
> an identifier with more than 128 bytes when query the file directly.
> I would like to ask the Calcite community whether there is any performance
> impact if we bump up the maximum length for a SQL identifier. If there is
> negligible performance impact, then, can we make the maximum length
> configurable in the SQL parser? We could make slightly modification to
> CombinedParser.jj template, to allow each system to set its own max length,
> with default still being 128.
> The approach to allow a configurable setting seems to be match what Postgres
> [2] is doing, which allows the length to be "raised by changing the
> NAMEDATALEN constant in src/include/pg_config_manual.h." [2]
> [Julian]
> Each system should be able to choose its own identifier max length.
> I’d prefer to make it configurable at runtime. Then we can test it. Add an
> extra parameter to SqlParser’s constructor, and have it call
> parser.setIdentifierMaxLength, similar to how it calls setQuotedCasing right
> now.
> Or if you want to go further, create
> interface SqlParser.Config {
> int identifierMaxLength();
> Casing quotedCasing();
> Casing unquotedCasing();
> }
> and replace all of the parameters of SqlParser’s constructor with one Config
> parameter.
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