This SQLite query takes ages in Flash but not in SQLite Administrator

Question

Hi
Are there ever occasions when flash adds time to queries?
I have a query that is taking almost 5 seconds on a database in Flash, yet when I put the same query into SQLite Administrator with that database loaded, it takes 15ms.
I set up a flash timer, and start it just before...
sqlStatement.execute(-1, new Responder( pass, fail ));
... and stop it and trace it as soon as Flash hits pass(); - so there's nothing else going on apart from the query to eat up time.
The database has an index that is being used according to EXPLAIN QUERY PLAN in SQLite Administrator. Does Flash use the same SQL code? It's as if it's ignoring the index.
Here's the query (I know there are a lot of COLLATE NOCASE statements - it's because my current table columns are not COLLATE NOCASE, and I'm not yet ready to set up a new table that has COLLATE NOCASE columns to copy the data into):
SELECT * FROM  (SELECT * FROM table1 WHERE col1 !="" COLLATE NOCASE ORDER BY col1 COLLATE NOCASE , col2 COLLATE NOCASE ASC, col3 COLLATE NOCASE ASC, col4 COLLATE NOCASE ASC ) UNION ALL SELECT * FROM (SELECT * FROM table1 WHERE col1="" COLLATE NOCASE ORDER BY col2 COLLATE NOCASE ASC, col3COLLATE NOCASE ASC, col4 COLLATE NOCASE ASC) LIMIT 10
Other queries on the same database are very fast, and seem to take the same time in Flash and SQLite Administrator.
Thanks for your thoughts.

Answer 1

You're limiting your results to 10, I'd also set the prefetch parameter of execute to 10 for posterity. Just a small thing.
How many columns are we talking about here? The SQL statement is fairly expensive (as you know) but I don't know how much data we're really talking about here or what the quality of the index tables are for this particular query. AIR also still needs to read and parse the result before handing it to you.
I'd go down the same route as you probably want to avoid. I'd trace every step of SQLConnection and SQLStatement to see exactly where the delay is occuring. I don't think you're going to get around this unless you just breakpoint from the connection and literally step through all the code yourself line by line until you notice the unusual delay and that isn't reliable because the delay could only occur when running the code full speed. I'd make sure you're running openAsync and trace every event and the timestamp on it (getTimer() - startTime). Something will show you the 4000-5000ms you're experiencing.