InterSystems FAQ rubric

For volatile tables (tables with many INSERTs and DELETEs), storage for bitmap indexes can become inefficient over time.

For example, suppose that there are thousands of data with the following definition, and the operation of bulk deletion with TRUNCATE TABLE after being retained for a certain period of time is repeatedly performed.

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Article
· Jun 8, 2023 1m read
How to write SELECT ... FOR UPDATE

InterSystems FAQ rubric

Since SELECT ... FOR UPDATE is implemented in many RDBMS as a method of explicit row lock acquisition, I think there are many cases where this function is used.

This syntax is not an error for InterSystems products, but it does not acquire row locks as expected.

This article will show you how to achieve equivalent functionality.

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InterSystems FAQ rubric

You can use the system routine ^DBSIZE to estimate the backup file size (see also Note 1).

^DBSIZE estimates the file size of full, cumulative, and differential backups of the databases selected in the database backup list.

The database backup list is created from [System Administration] > [Configuration] > [Database Backup] > [Database Backup List] in the Management Portal.

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