This article lists out extensive list of example scripts for looping through table records one row at a time. This article covers the examples for the following.

Hi Tom, From my knowledge of oracle, i understand that SELECT FOR UPDATE clause acquires row locks. In that case, if in a given table, when my query updates one set.

Table Partitioning in SQL Server - Partition Switching. Inserts, updates and deletes on large tables can be very slow and expensive, cause locking and blocking, and even fill up the transaction log. One of the main benefits of table partitioning is that you can speed up loading and archiving of data by using partition switching. Free Software Download Sites With Cracks here. Partition switching moves entire partitions between tables almost instantly. It is extremely fast because it is a metadata- only operation that updates the location of the data, no data is physically moved. New data can be loaded to separate tables and then switched in, old data can be switched out to separate tables and then archived or purged.

• It isn’t too hard to get this information out of SQL Server. But before you open SSMS.
• SQL's UPDATE statement makes it easy to update one or more records in a database table. The most common UPDATE statement pattern assigns static or parameterized.

All data preparation and manipulation can be done in separate tables without affecting the partitioned table. Partition Switching Requirements. There are always two tables involved in partition switching. Data is switched from a source table to a target table. The target table (or target partition) must always be empty.(The first time I heard about partition switching, I thought it meant “partition swapping“. I thought it was possible to swap two partitions that both contained data. This is currently not possible, but I hope it will change in a future SQL Server version.)Partition switching is easy – as long as the source and target tables meet all the requirements : ) There are many requirements, but the most important to remember are: The source and target tables (or partitions) must have identical columns, indexes and use the same partition column.

The source and target tables (or partitions) must exist on the same filegroup. The target table (or partition) must be empty. If all the requirements are not met, SQL Server is happy to tell you exactly what went wrong and provides detailed and informative error messages. Some of the most common examples are listed near the end of this blog post. Partition Switching Examples. Partitions are switched by using the ALTER TABLE SWITCH statement. You ALTER the source table (or partition) and SWITCH to the target table (or partition).

There are four ways to use the ALTER TABLE SWITCH statement: Switch from a non- partitioned table to another non- partitioned table. Load data by switching in: Switch from a non- partitioned table to a partition in a partitioned table. Archive data by switching out: Switch from a partition in a partitioned table to a non- partitioned table. Switch from a partition in a partitioned table to a partition in another partitioned table.

The following examples use code from the previous Table Partitioning Basics blog post. It is important to notice that these examples are meant to demonstrate the different ways of switching partitions, they do not create any indexes and they map all partitions to the . These examples are not meant to be used in real- world projects. Switch from Non- Partitioned to Non- Partitioned. The first way to use the ALTER TABLE SWITCH statement is to switch all the data from a non- partitioned table to an empty non- partitioned table.

ALTER TABLE Source SWITCH TO Target. ALTERTABLESource. SWITCHTOTarget. Before switch: After switch: This is probably not used a lot, but it is a great way to start learning the ALTER TABLE SWITCH statement without having to create partition functions and partition schemes. Drop objects if they already exist. IF EXISTS (SELECT * FROM sys.

WHERE name = N'Sales. Source'). DROP TABLE Sales. Source. IF EXISTS (SELECT * FROM sys. WHERE name = N'Sales. Target'). DROP TABLE Sales.

Target. - - Create the Non- Partitioned Source Table (Heap) on the ? The target table 'Sales. Target' must be empty. SUPER FAST!- - Turn off statistics. SETSTATISTICSTIMEOFF; -- Verify row count after switch.

SELECTCOUNT(*)FROMSales. Source; -- 0 rows. SELECTCOUNT(*)FROMSales. Target; -- 1. 46.

If we try to switch again we will get an error: ALTERTABLESales. Source. SWITCHTOSales. Target; -- Msg 4. ALTER TABLE SWITCH statement failed. The target table 'Sales. Target' must be empty.- - But if we try to switch back to the now empty Source table, it works: ALTERTABLESales.

Target. SWITCHTOSales. Source; -- (.. STILL SUPER FAST!)2. Load data by switching in: Switch from Non- Partitioned to Partition. The second way to use the ALTER TABLE SWITCH statement is to switch all the data from a non- partitioned table to an empty specified partition in a partitioned table. ALTER TABLE Source SWITCH TO Target PARTITION 1. ALTERTABLESource. SWITCHTOTarget. PARTITION1.

Before switch: After switch: This is usually referred to as switching in to load data into partitioned tables. The non- partitioned table must specify WITH CHECK constraints to ensure that the data can be switched into the specified partition.

Drop objects if they already exist. IF EXISTS (SELECT * FROM sys. WHERE name = N'Sales. Source'). DROP TABLE Sales. Source. IF EXISTS (SELECT * FROM sys.

WHERE name = N'Sales. Target'). DROP TABLE Sales.

Target. IF EXISTS (SELECT * FROM sys. We get an error. - - Msg 4. ALTER TABLE SWITCH statement failed. Check constraints of source table 'Sales. Source'. - - allow values that are not allowed by range defined by partition 1 on target table 'Sales'.

Is it really that fast..? We get an error: -- Msg 4. ALTER TABLE SWITCH statement failed.

Check constraints of source table 'Sales. Source' - - allow values that are not allowed by range defined by partition 1 on target table 'Sales'.- - Add constraints to the source table to ensure it only contains data with values - - that are allowed in partition 1 on the target table. ALTERTABLESales. Source.

WITHCHECKADDCONSTRAINTck. Min. Sales. Date. CHECK(Sales. Date. ISNOTNULLANDSales. Date> ='2. 01. ALTERTABLESales. Source.

WITHCHECKADDCONSTRAINTck. Max. Sales. Date. CHECK(Sales. Date.

ISNOTNULLANDSales. Date< '2. 01. 3- 0. Try again. Is it really that fast..? ALTERTABLESales. Source.

SWITCHTOSales. Target. PARTITION1; -- YEP! SUPER FAST!- - Turn off statistics. SETSTATISTICSTIMEOFF; -- Verify row count after switch. SELECTCOUNT(*)FROMSales.

Source; -- 0 rows. SELECT  pstats. partition.

Archive data by switching out: Switch from Partition to Non- Partitioned. The third way to use the ALTER TABLE SWITCH statement is to switch all the data from a specified partition in a partitioned table to an empty non- partitioned table. ALTER TABLE Source SWITCH PARTITION 1 TO Target. ALTERTABLESource. SWITCHPARTITION1.

TOTarget. Before switch: After switch: This is usually referred to as switching out to archive data from partitioned tables. Drop objects if they already exist.

IF EXISTS (SELECT * FROM sys. WHERE name = N'Sales. Source'). DROP TABLE Sales. Source. IF EXISTS (SELECT * FROM sys. WHERE name = N'Sales.

Target'). DROP TABLE Sales. Target. IF EXISTS (SELECT * FROM sys.

SUPER FAST!- - Turn off statistics. SETSTATISTICSTIMEOFF; -- Verify row count after switch. SELECT  pstats. partition.

Switch from Partition to Partition. The fourth way to use the ALTER TABLE SWITCH statement is to switch all the data from a specified partition in a partitioned table to an empty specified partition in another partitioned table. ALTER TABLE Source SWITCH PARTITION 1 TO Target PARTITION 1.

ALTERTABLESource. SWITCHPARTITION1. TOTarget. PARTITION1. Before switch: After switch: This can be used when data needs to be archived in another partitioned table. Drop objects if they already exist. IF EXISTS (SELECT * FROM sys. WHERE name = N'Sales.

Source'). DROP TABLE Sales. Source. IF EXISTS (SELECT * FROM sys. WHERE name = N'Sales. Target'). DROP TABLE Sales. Target. IF EXISTS (SELECT * FROM sys.

SUPER FAST!- - Turn off statistics. SETSTATISTICSTIMEOFF; -- Verify row count after switch. SELECT  pstats. partition. You can see all messages related to ALTER TABLE SWITCH by executing the following query, it is also quite a handy requirements checklist.

SELECT message. New data can be loaded to separate tables and then switched in, old data can be switched out to separate tables and then archived or purged. There are many requirements for switching partitions.