Check Index Fragmentation in a SQL Server If we run INSERT, UPDATE or DELETE queries frequently than we can see indexes on the particular table are fragmented. And the SQL query may run slower as they may choose the non-optimal execution plan. Below script can be used for checking how much percentages of an indexes gets fragmented on a database. so that we can rebuild or reorganise the indexes. SELECT OBJECT_NAME(ind.OBJECT_ID) AS TableName, ind.name AS IndexName, indexstats.index_type_desc AS IndexType, indexstats.avg_fragmentation_in_percent FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, NULL) indexstats INNER JOIN sys.indexes ind ON ind.object_id = indexstats.object_id AND ind.index_id = indexstats.index_id WHERE indexstats.avg_fragmentation_in_percent > 10--You can specify the percent as you want AND ind.name is not null ORDER BY indexstats.avg_fragmentation_in_percent DESC

How to fill in last non-null value partition by user? Redshift SQL

Rajan

I want to find a way to get the last non-null value for a purchase of a user. For example, I have this:

date        | user_id | purchase_amount
2020-01-01  | 1       | 39
2020-01-04  | 1       | null
2020-01-10  | 1       | 90
2020-01-15  | 1       | null

I want if to fill in the following way:

date        | user_id | purchase_amount
2020-01-01  | 1       | 39
2020-01-04  | 1       | 39
2020-01-10  | 1       | 90
2020-01-15  | 1       | 90

Right now, I am using a LEAD function partition by user_id but it still would consider even non-null values. How to approach this?