Search found 5 matches
- Fri Feb 22, 2013 11:45 pm
- Forum: PHP
- Topic: EXPLAIN queries fail
- Replies: 0
- Views: 14086
EXPLAIN queries fail
I'm connecting to Vertica via ODBC. Normal queries work: $db->query("SELECT 1")->fetchAll(); However EXPLAIN queries: $db->query("EXPLAIN SELECT 1")->fetchAll(); fail with error: PDOException: SQLSTATE[SL009]: <<Unknown error>>: 0 [unixODBC][Driver Manager]No columns were bound prior to calling SQLF...
- Fri Feb 01, 2013 2:41 pm
- Forum: Vertica Performance Tuning
- Topic: Loads into pre-join projections of 2 fact tables don't scale
- Replies: 6
- Views: 14570
Re: Loads into pre-join projections of 2 fact tables don't s
We have come to the bottom of this: Inserting into pre-join projections does not recognize the transitivity of predicates based on join keys in pre-join projections. As a consequence, some INSERTs into pre-join projections between two large tables that could be O(inserted_data) are O(existing_data),...
- Fri Feb 01, 2013 12:39 pm
- Forum: Vertica Performance Tuning
- Topic: Loads into pre-join projections of 2 fact tables don't scale
- Replies: 6
- Views: 14570
Re: Loads into pre-join projections of 2 fact tables don't s
Based on your feedback and instructions from Vertica support, I have tried two more things 1) Single node, explicitly sorted projections, no RESEGMENT and no JOIN at all in the EXPLAIN ( vertica-prejoin-scaling-test-2.sh ) ------------------------------ QUERY PLAN DESCRIPTION: ----------------------...
- Wed Jan 30, 2013 8:08 pm
- Forum: Vertica Performance Tuning
- Topic: Loads into pre-join projections of 2 fact tables don't scale
- Replies: 6
- Views: 14570
Re: Loads into pre-join projections of 2 fact tables don't s
Hi Becky, Similarly to how it's done in the example reproduction script, we 1. insert into a temp table, using JDBC batch inserts (which under the hood should get converted to COPY), then 2. do "insert into final_table select * from temp_table". Indeed we have not tried doing COPY directly into the ...
- Wed Jan 30, 2013 1:41 pm
- Forum: Vertica Performance Tuning
- Topic: Loads into pre-join projections of 2 fact tables don't scale
- Replies: 6
- Views: 14570
Loads into pre-join projections of 2 fact tables don't scale
Hello, We are trying to create a pre-join projection that joins two large fact tables. The problem is that INSERTs are slow: they take O(existing_data), not O(added_data). In practice, this means that after importing a couple of days worth of data, they become prohibitively slow. The projections are...