CXPACKET:
o Happens when a parallel query runs and some threads are slower than others.
o This wait type is common in highly parallel environments.

How to resolve CXPACKET wait in SQL Server

Adjust the MAXDOP Setting:
o The MAXDOP (Maximum Degree of Parallelism) setting controls the number of
processors used for parallel query execution. Reducing the MAXDOP value can help
reduce CXPACKET waits.
o You can set the MAXDOP value at the server level using the following command:

EXEC sp_configure 'show advanced options', 1;
RECONFIGURE;
EXEC sp_configure 'max degree of parallelism', 4; -- Adjust the 
value as needed
RECONFIGURE;

Hint

You can also set the MAXDOP value at the query level using the OPTION (MAXDOP
n) hint

Update Statistics:

UPDATE STATISTICS YourTableName;

Monitor and Adjust Cost Threshold for Parallelism:
The cost threshold for parallelism setting defines when SQL Server will use parallel execution for a query. Raising this value can help lower unnecessary parallelism.

EXEC sp_configure 'show advanced options', 1;
RECONFIGURE;
EXEC sp_configure 'cost threshold for parallelism', 50; -- Adjust 
the value as needed
RECONFIGURE;

SQL Server Profiler to identify and optimize poorly performing queries.