[jira] [Resolved] (CASSANDRA-8254) Query parameters (and more) are limited to 65,536 entries

["Aleksey Yeschenko (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CASSANDRA-8254?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Aleksey Yeschenko resolved CASSANDRA-8254.
------------------------------------------
    Resolution: Not a Problem

As mentioned by Tyler, this really isn't a problem if you bind ? to a list of tuples instead.

If that doesn't work for some reason, feel free to reopen.

> Query parameters (and more) are limited to 65,536 entries
> ---------------------------------------------------------
>
>                 Key: CASSANDRA-8254
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8254
>             Project: Cassandra
>          Issue Type: Bug
>          Components: API
>            Reporter: Nicolas Favre-Felix
>
> Parameterized queries are sent over the wire as a string followed by a list of arguments. This list is decoded in QueryOptions.Codec by CBUtil.readValueList(body), which in turn reads a 16-bit short value from the wire as the number of values to deserialize.
> Sending more values leads to a silent overflow, sometimes reported by the driver as a protocol error as other values are deserialized incorrectly.
> 64k sounds like a lot, but tables with a large number of clustering dimensions can hit this limit when fetching a few thousand CQL rows only with an IN query, e.g.
> {code}
> SELECT * FROM sensor_data WHERE a=? and (b,c,d,e,f,g,h,i) IN ((?,?,?,?,?,?,?,?), (?,?,?,?,?,?,?,?), (?,?,?,?,?,?,?,?), (?,?,?,?,?,?,?,?) ... )
> {code}
> Here, having 8 dimensions in the clustering key plus 1 in the partitioning key restricts the read to 8,191 CQL rows.
> Some other parts of Cassandra still use 16-bit sizes, for example preventing users to fetch all elements of a large collection (CASSANDRA-6428). The suggestion at the time was "we'll fix it in the next iteration of the binary protocol", so I'd like to suggest switching to variable-length integers as this would solve such issues while keeping messages short.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)