[IGNITE-12382] Clarify "collocated" flag documentation

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.6
• Fix Version/s: 2.8
• Component/s: documentation
• Assignee: Artem Budnikov
• Reporter: Denis A. Magda
• Created: 18/Nov/19 21:03
• Updated: 04/Dec/19 16:17
• Resolved: 22/Nov/19 22:48

Description

Documentation of the JDBC and ODBC drivers doesn't explain when and why the "collocated" flag needs to be set. The docs are vague and not clear:
https://apacheignite-sql.readme.io/docs/jdbc-driver
https://apacheignite-sql.readme.io/docs/connection-string-and-dsn

In fact, the optimization is useful for queries with GROUP BY operand. The docs need to be improved with the content of the Javadoc and a summary shared in the dev list discussion:
https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/cache/query/SqlFieldsQuery.html#isCollocated--
http://apache-ignite-developers.2346864.n4.nabble.com/Collocated-replicatedOnly-flags-for-Thin-JDBC-driver-td44357.html