[
https://issues.apache.org/jira/browse/CASSANDRA-17198?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17492515#comment-17492515
]
Benjamin Lerer edited comment on CASSANDRA-17198 at 2/15/22, 10:34 AM:
-----------------------------------------------------------------------
[~subkanthi] Looking at the patch there are several point that would need to be
changed.
* Without indexes LIKE restrictions can only be performed through filtering.
That means that the queries should fail if {{ALLOW FILTERING}} is not
specified. As shown by some of the unit tests it is not the case. This should
be changed for clustering columns by modifying
{{StatementRestrictions.processClusteringColumnRestrictions}} and for the
partition keys by modifying {{PartitionKeySingleRestrictionSet.needFiltering}}.
For that last one you will need to add a new {{hasLike}} method to
{{Restrictions}} and use it.
* If the user attempt to use a LIKE restriction on a column which is not a
string type the error can be confusing. The logic within
{{SingleColumnRelation.newLikeRestriction}} can be changed to validate that the
type of the receiver (for a LIKE you are guaranty to have only one) is a
instanceof StringType.
* It should be good to test that LIKE statement cannot be used on UPDATE or
DELETE statements.
was (Author: blerer):
[~subkanthi] Looking at the patch there are several point that would need to be
changed.
* Without indexes LIKE restrictions can only be performed through filtering.
That means that the queries should fail if {{ALLOW FILTERING}} is not
specified. As shown by some of the unit tests it is not the case. This should
be changed for clustering columns by modifying
{{StatementRestrictions.processClusteringColumnRestrictions}} and for the
partition keys by modifying {{PartitionKeySingleRestrictionSet.needFiltering}}.
For that last one you will need to add a new {{hasLike}} method to
{{Restrictions}} and use it.
* If the user attempt to use a LIKE restriction on a column which is not a
string type the error can be confusing. The logic within
{{SingleColumnRelation.newLikeRestriction}} can be changed to validate that the
type of the receiver (for a LIKE you are guaranty to have only one) is a
instanceof StringType.
> Allow to filter using LIKE predicates
> -------------------------------------
>
> Key: CASSANDRA-17198
> URL: https://issues.apache.org/jira/browse/CASSANDRA-17198
> Project: Cassandra
> Issue Type: Improvement
> Components: CQL/Syntax
> Reporter: Benjamin Lerer
> Assignee: Kanthi Subramanian
> Priority: Normal
> Labels: AdventCalendar2021, lhf
> Fix For: 4.x
>
>
> {{LIKE}} predicates can only be used with the SASI indices. In several
> usecases (e.g. querying the {{settings}} virtual table) it makes sense to
> support them for filtering.
> +Additional information for newcomers:+
> There are some checks in the {{StatementRestrictions}} constructor and on
> {{LikeRestriction}} that need to be removed for allowing filtering using LIKE
> on clustering and regular columns.
> For filtering on partition columns the {{needFiltering}} methods in
> {{PartitionKeySingleRestrictionSet}} will need to be modified to return true
> when LIKE predicate are used.
> The unit tests should go in {{SelectTest}}.
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org
