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From Mikhail Fokanov <wmas...@mail.ru>
Subject Polymorphic SQL queries
Date Tue, 27 Dec 2016 11:48:35 GMT
Hi,

               I use Apache Ignite for high-loaded portal. Performance of SQL queries
are ok, but I can't find a way of implementing polymorphic SQL queries. I need to index all
sub-classes of the class in SINGLE_TABLE strategy (ex. ImageFile, PdfFile as sub-classes of
File), in order to execute queries like (select * from File where createdDate > 0). For
such query I can use "union all" and search all sub-classes, but now the amount of sub-classes
is 15 and this solution looks bad. Also I need to join User table with File table and I think
"union all" will be bad for performance in such case. Am I right? I try to manage Query Entities
in CacheConfiguration, but have no success. Can I implement some hack to store entities of
all sub-classes in the same table (File) and execute queries on it?
               Also I mention that in guide ( http://apacheignite.gridgain.org/docs/sql-queries
) sql joins are always CROSS. Can I use INNER joins and does it improve the performance of
query?

--
Best Regards,
Mikhail Fokanov
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