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https://issues.apache.org/jira/browse/PHOENIX-1812?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14580958#comment-14580958
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Thomas D'Silva commented on PHOENIX-1812:
-----------------------------------------
[~jamestaylor]
I have uploaded a second patch. I modified PTableRef to include
resolvedTimeStamp.
The extra RPC call to getTable for queries was happening because in
QueryCompiler.compileSingleFlatQuery the following if statement was evaluating
to false event though both TableRefs references the same table, one of them had
a null alias.
{code}
// Don't pass groupBy when building where clause expression, because we
do not want to wrap these
// expressions as group by key expressions since they're pre, not post
filtered.
if (innerPlan == null && !tableRef.equals(resolver.getTables().get(0)))
{
context.setResolver(FromCompiler.getResolverForQuery(select,
this.statement.getConnection()));
}
{code}
it works correctly when I modified TableRef.equals to not compare the alias if
one of them is null:
{code}
- // FIXME: a null alias on either side should mean a wildcard and
should not fail the equals check
- if ((alias == null && other.alias != null) || (alias != null &&
!alias.equals(other.alias))) return false;
+ // a null alias on either side should mean a wildcard and should not
fail the equals check
+ if ((alias != null && other.alias != null &&
!alias.equals(other.alias))) return false;
{code}
In UpdateCacheIT testUpdateCacheForTxnTable()
For transactional tables in PhoenixStatment.executeQuery() since the plan is
compiled before a transaction is started,
the first call to connection.getTable() will not have a valid txn timestamp,
the second call will have a valid txn timestamp, and the third will use the
table cached at the txn timestamp for a total of two rpcs.
I think we can't change executeQuery() to start a transaction before compiling
the plan, because then it will always make a rpc call to the txn manager (even
if the query doesnt have any transactional tables).
> Only sync table metadata when necessary
> ---------------------------------------
>
> Key: PHOENIX-1812
> URL: https://issues.apache.org/jira/browse/PHOENIX-1812
> Project: Phoenix
> Issue Type: Sub-task
> Reporter: James Taylor
> Assignee: Thomas D'Silva
> Attachments: PHOENIX-1812.patch
>
>
> With transactions, we hold the timestamp at the point when the transaction
> was opened. We can prevent the MetaDataEndpoint getTable RPC in
> MetaDataClient.updateCache() to check that the client has the latest table if
> we've already checked at the current transaction ID timestamp. We can keep
> track of which tables we've already updated in PhoenixConnection.
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