To copy database without statistics, add NO_STATISTICS and NO_QUERYSTORE to DBCC CLONEDATABASE. This post shows why that matters, because histograms and Query Store texts hold real values. It also shows the plan estimate that changes, how to make a clone writable, and what VERIFY_CLONEDB does.
Clone Database in SQL Server With DBCC CLONEDATABASE
Clone Database in SQL Server with DBCC CLONEDATABASE and you copy the structure and the statistics without a single row. This post runs the command on a demo database, checks what the clone holds and what it leaves out, and shows that the optimizer builds the same plan from the copied statistics.
Statistics Sample Percent and PERSIST_SAMPLE_PERCENT
The statistics sample percent decides how many rows SQL Server reads when it updates a statistic. A tested demo on 1,000,000 rows shows the default sample of 35.5 percent, a FULLSCAN of 100 percent, and the way PERSIST_SAMPLE_PERCENT keeps 100 percent for later updates, including an automatic one. It also shows that a sampled update can be slower than a full scan.
STATISTICS TIME and IO: Turn Them On for Every SSMS Query
To get STATISTICS TIME and IO for every query, tick two boxes in the SSMS options once instead of typing SET STATISTICS in each window. This post builds a small demo, reads the output line by line, shows that a SELECT and an UPDATE both report their cost, and explains which windows the option affects.
Filtered Statistics: Fixing Estimates for Skewed Data
Use filtered statistics to describe skewed customer values, inspect histograms, and test estimates under literal and parameterized queries.
Index Slows Down SELECT? What an Unused Index Costs You
An index slows down SELECT queries only in small ways when the plan never reads it. This post measures compile memory with twelve unused indexes, shows the plan change when a related index appears, and counts what every insert and update pays. The real bill arrives on writes.
Async Statistics Updates: Stopping Queries From Stalling
Diagnose synchronous statistics refresh waits, enable async statistics updates, and judge when fresh estimates still matter more.