Howdy! I've read through the docs at https://apacheignite.readme.io but couldn't find a definitive answer (even started diving into the source, but figured I'd try here before going further). The following is listed as a feature on the Apache Ignite Datagrid website:
"Ignite provides full query consistency. Updates that happened after the query execution started do not affect the query result." >From the docs and JIRA ticket (https://issues.apache.org/jira/browse/IGNITE-3478), it appears that SQL queries do not yet support MVCC in relation to DataGrid Transactions (e.g. If writing A and B in a transaction, able to get new A value but old B value). So, for getAll(), ScanQuery, etc. how is this supported? Is it only when the cache is set to TRANSACTIONAL? I tried a quick test which modifies an object of an ATOMIC cache during the SQL cursor iteration (and small page size), but the previous value was returned. Though I'm not sure if there is an optimization/minimum value on the page size. Fundamentally, my question is under what conditions (atomicity mode, query type, etc.) is the query consistency guaranteed and how does Ignite ensure this (e.g. MVCC, local cache for ongoing queries, etc.) Thanks, Jeff -- View this message in context: http://apache-ignite-users.70518.x6.nabble.com/Does-the-Query-Consistency-feature-use-MVCC-tp14497.html Sent from the Apache Ignite Users mailing list archive at Nabble.com.
