yugabyte/yugabyte-db

YCQL -- Disallow GROUP BY syntax

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#13,956 opened on Sep 9, 2022

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Description

Jira Link: DB-3446

We don't support the GROUP BY clause in YCQL (only in YSQL) but it is allowed in the syntax (presumably by mistake).

I think the issue is that the group_clause was not disallowed in the parser: https://github.com/yugabyte/yugabyte-db/blob/master/src/yb/yql/cql/ql/parser/parser_gram.y#L2519 (see for instance the PARSER_UNSUPPORTED calls for some of the other sub-cases below -- the should be there for the top-level non-empty case).

In terms of functionality, from this code: https://github.com/yugabyte/yugabyte-db/blob/master/src/yb/yql/cql/ql/parser/parser_gram.y#L2178 it looks like we are just ignoring the GROUP BY clause if set.

Finally, if backwards compatibility is an issue we can make this a warning rather than an error by default (for GROUP BY specifically.

Contributor guide

Research direction
Inspect the parser gram.y file, specifically the group clause handling around line 2178, and add PARSER UNSUPPORTED as done for other clauses.
Tech stack
c
Domain
databasebackend
Issue type
Bug
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3
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1-2 days
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Active
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Clear
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CYACC/Bison
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60