I'm trying to debug the source of a SQL timeout in a web application that I maintain. I have the source code of the C# code behind, so I know exactly what code is running. I have debugged the appli...

I have table contains three columns. If I select NVARCHAR(MAX) column in my select statement, I see poor performance. Is it possible to create index on a NVARCHAR(MAX) column?. CREATE TABLE TEST (...

I'm struggling getting my head around the Django's ORM. What I want to do is get a list of distinct values within a field on my table .... the equivalent of one of the following: SELECT DISTINCT my...

I'm curious which of the following below would be more efficient? I've always been a bit cautious about using IN because I believe SQL Server turns the result set into a big IF statement. For a la...

I know this is a common question and I have read several other posts and papers but I could not find one that takes into account indexed fields and the volume of records that both queries could ret...

Does anyone know when, specifically, the clock for $upstream_response_time begins and ends? The documentation seems a bit vague: keeps time spent on receiving the response from the upstream ser...

I am new with Cassandra CQL, I want to get the Cassandra query execution time. Can i do it in CQL shell by storing the current time in the variable, execute the query and then store the current tim...

I've been searching for this for a week now, and I'm afraid this may not exist [yet]. I wanted to use an index that spans multiple tables in PostgreSQL. Oracle and SQL server seem to implement them...

I'm new to SQL and I have a question. I have this SQL code: DROP TABLE if exists students; DROP TABLE if exists grades; CREATE TABLE students( s_id integer NOT NULL PRIMARY KEY, s_name text, ...

Let us have the following data IF OBJECT_ID('dbo.LogTable', 'U') IS NOT NULL DROP TABLE dbo.LogTable SELECT TOP 100000 DATEADD(day, ( ABS(CHECKSUM(NEWID())) % 65530 ), 0) datesent INTO [LogTa...

So I have a small and simple Redis database. It contains 136689 keys whose values are hash maps containing 27 fields. I'm accessing the table through the Python interface on the server node, and ne...

I am doing a PoC to check if Postgres is the right candidate for our use cases. I have the following workload: Data query: Presentation layer will retrieve data every 15 mins for last 2 weeks Da...

Like many Postgres n00bs we have a lot of tables with foreign key constraints that are not indexed. I some cases this should not be a big performance hit - but this would be subject for further ana...

I am aggregating data from a Postgres table, the query is taking approx 2 seconds which I want to reduce to less than a second. Please find below the execution details: Query select a.search...

I have a table with over 260 million records. I have created partition for the table and also indexed it. CREATE TABLE qt_al_90k ( rec_id integer, user_id integer, user_text text, user_number ...

I have a queryset that returns a lot of data, it can be filtered by year which will return around 100k lines, or show all which will bring around 1 million lines. The objective of this annotate is...

So, I'm getting a number of instances of a particular entity by id: for(Integer songId:songGroup.getSongIds()) { session = HibernateUtil.getSession(); Song song = (Song) session.get(Song.class,i...

I have a query which is never finishing (left running for over 24 hours and was still going). Now there isn't a huge amount of data in each table so I can only assume it is the efficiency of the q...

this a poor performancing query I have ... what have I done so wrong? Please help me it is executed tons of times in my system, solving that will give me a ladder to heaven I gave a check on the s...

We have ~20M (hotel offers) documents stored in elastic(1.6.2) and the point is to group documents by multiple fields (duration, start_date, adults, kids) and select one cheapest offer out of each ...

I have a problem with this query: SELECT a.* FROM smartressort AS s JOIN smartressort_to_ressort AS str ON s.id = str.smartressort_id JOIN article_to_ressort AS atr ON str.ressort_id = atr.resso...

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....

Context We appear to be having an Entity Framework 6.x related issue. We've spent weeks attempting to nail down performance issues and fixed most if not all which we can find/think of. In short, w...

I have a field which is a varchar(20) When this query is executed, it is fast (Uses index seek): SELECT * FROM [dbo].[phone] WHERE phone = '5554474477' But this one is slow (uses index scan). ...

I have a not-so-complex (imho) filtering logic based on several conditions in my Django models. There is one particular query which takes an inusual amount of time to finish. The query is built b...