query-performance

I need to query records from a DB2 database using LINQ. I have entities that have been generated from the DB schema and am attempting to perform a LINQ query using Skip and Take. The underlying table has like 25 columns and maybe a million records. When I execute the query without the "Skip()" it takes approximately .508 milliseconds to complete. When I include Skip() it takes close to 30 seconds. Big difference. Can anyone tell me why this is happening? UPDATE: Here is the LINQ query I am using. var x = 30; var results = context.ASSET_T .OrderBy(c => c.ASSET_ID) .Skip(x) .Take(x) .ToList();

I'm trying to debug a very strange discrepency between 2 seperate cosmos db collection that on face value are configured the same. We recently modified some code that executed the following query. OLD QUERY SELECT * FROM c WHERE c.ProductId = "CODE" AND c.PartitionKey = "Manufacturer-GUID" NEW QUERY SELECT * FROM c WHERE (c.ProductId = "CODE" OR ARRAY_CONTAINS(c.ProductIdentifiers, "CODE")) AND c.PartitionKey = "Manufacturer-GUID" The introduction of that Array_Contains call in the production environment has tanked the performance of this query from ~3 RU/s ==> ~6000 RU/s. But only in the

I use Firebase database on my Android app. Normally, it works fine. But when the database is getting larger, the query performance is getting worse. I added about 5k record on database (under "elk" and "su" nodes), then I queried on database (on "cut" and "user" nodes) but all the queries are very very slow. I defined data index on database rules but it did not work. How can I solve that problem? Here are my queries : // query to get the zones followed by user FirebaseDatabase.getInstance() .getReference() .child("user") .child(userID) .child("zones"); // query to get cuts on a zone