[PHOENIX-1315] Optimize query for Pig loader

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.2.0, 3.2.0
• Assignee: maghamravikiran
• Reporter: James R. Taylor
• Created: 04/Oct/14 05:06
• Updated: 21/Nov/15 02:17
• Resolved: 07/Oct/14 08:27

Description

I came across this with a recent change I was making. Why is the call to queryPlan.iterators() necessary in PhoenixInputFormat?

    private QueryPlan getQueryPlan(final JobContext context) throws IOException {
        Preconditions.checkNotNull(context);
        if(queryPlan == null) {
            try{
                final Connection connection = getConnection();
                final String selectStatement = getConf().getSelectStatement();
                Preconditions.checkNotNull(selectStatement);
                final Statement statement = connection.createStatement();
                final PhoenixStatement pstmt = statement.unwrap(PhoenixStatement.class);
                this.queryPlan = pstmt.compileQuery(selectStatement);
                // FIXME: why is getting the iterator necessary here, as it will
                // cause the query to run.
                this.queryPlan.iterator();
            } catch(Exception exception) {
                LOG.error(String.format("Failed to get the query plan with error [%s]",exception.getMessage()));
                throw new RuntimeException(exception);
            }
        }
        return queryPlan;
    }