FMDB - Improve FMResultSet speed

Question

This code take a very long time to run. I have roughly 100,000 records. Each step takes roughly the same mount of time.... get the result from FMResultSet and reading it into the 3 arrays. I tried using two select statements. One to get the result count and then allocating that amount in the mutableArray. No performance difference. Any suggestions to improve speed?

FMResultSet *results = [database executeQuery:@"SELECT FriendlyName, Serial, Barcode FROM Inventory, Company WHERE Inventory.friendlyName <> '' AND Company.CompanyID = Inventory.companyID AND Company.CompanyName = ?", selectedCompany];

arrayFriendlyName =[[NSMutableArray alloc]init];
arraySerial = [[NSMutableArray alloc]init];
arrayBarcode = [[NSMutableArray alloc]init];


while([results next]) {

    [arrayFriendlyName addObject:[results stringForColumn:@"FriendlyName"]];
    [arrayBarcode addObject:[results stringForColumn:@"Barcode"]];
    [arraySerial addObject:[results stringForColumn:@"Serial"]];

}

[database close];

Answer 1

Depending on your database structure any object-oriented wrapper around sqlite can be quite slow when it comes to thousands of rows. You can try to speed it up by directly accessing the sqlite database , without using any object oriented wrapper. As you don't need any relations (at least in your example code), you won't loose any relevant functionality - and it will be as fast as it can get.

As always, Ray Wenderlich is a good resource to look at: http://www.raywenderlich.com/913/sqlite-tutorial-for-ios-making-our-app

In case you didn't do it already, you can also have a look whether you have your indexes set right on your query - as you are joining two tables, having no indexes on the joined columns can seriously impact your performance.