How do I delete a large number of records in SQL Server?
Deleting large portions of a table isn’t always the only answer. If you are deleting 95% of a table and keeping 5%, it can actually be quicker to move the rows you want to keep into a new table, drop the old table, and rename the new one. Or copy the keeper rows out, truncate the table, and then copy them back in.
How do I delete a billions of records in SQL Server?
3 Answers. if you want to delete all billion records, just truncate it. If you want some of the record exist you can use query DELETE FROM … select 1 — Just to force @@rowcount > 0 while @@ROWCOUNT > 0 delete from [table] [where …]
How do you bulk delete in SQL?
No. You want a DELETE with a WHERE clause: this is standard SQL. What you can do is batch deletes like this: SELECT ‘Starting’ –sets @@ROWCOUNT WHILE @@ROWCOUNT <> 0 DELETE TOP (xxx) MyTable WHERE …
How do I delete a large data table in SQL without logging?
On the other hand if you are deleting more than 80-90 Percent of the data, say if you have total of 11 million rows and you want to delete 10 million another way would be to Insert these 1 million rows (records you want to keep) to another staging table. Truncate this large table and Insert back these 1 million rows.
How do I delete top 20 records in SQL?
SQL Server DELETE Top Statement. In SQL Server, DELETE TOP statement is used to delete the records from a table and limit the number of records deleted regarding a fixed value or percentage. Syntax: DELETE TOP (top_value) [ PERCENT ]
Which is better TRUNCATE or delete?
Truncate removes all records and doesn’t fire triggers. Truncate is faster compared to delete as it makes less use of the transaction log. Truncate is not possible when a table is referenced by a Foreign Key or tables are used in replication or with indexed views.
How do I DELETE multiple records?
To delete multiple records in a report:
- Create (or open) a table report that contains the records you want to delete.
- Select the check boxes next to the records you want to delete, as shown in the example:
- Select Delete above the table. A dialog appears to confirm the deletion.
What is difference between truncate and DELETE?
The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log.
How do I DELETE table records?
To remove one or more rows in a table:
- First, you specify the table name where you want to remove data in the DELETE FROM clause.
- Second, you put a condition in the WHERE clause to specify which rows to remove. If you omit the WHERE clause, the statement will remove all rows in the table.
How do I quickly DELETE in SQL?
Removing all the rows fast with truncate. Using create-table-as-select to wipe a large fraction of the data. Dropping or truncating partitions.
Remove Rows with Create-Table-as-Select
- Create a new table saving the rows you want to keep.
- Truncate the original table.
- Load the saved rows back in with insert as select.
What is Rowcount in SQL?
SQL Server @@ROWCOUNT is a system variable that is used to return the number of rows that are affected by the last executed statement in the batch. … @@ROWCOUNT is used frequently in the loops to prevent the infinite loops and stop the current process when all the target rows are processed.
What is SQL Rowcount?
%ROWCOUNT yields the number of rows affected by an INSERT , UPDATE , or DELETE statement, or returned by a SELECT INTO statement. … The value of the SQL%ROWCOUNT attribute refers to the most recently executed SQL statement from PL/SQL. To save an attribute value for later use, assign it to a local variable immediately.