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22 Απρ 2010 · If the hidden purpose of your question is to DROP the index before making INSERT to a large table, then this is a useful one-liner: DROP INDEX IF EXISTS [IndexName] ON [dbo].[TableName] This syntax has been available since SQL Server 2016.
13 Μαΐ 2024 · DROP INDEX index_name ON { database_name.schema_name.table_name | schema_name.table_name | table_name } [ ; ] Arguments IF EXISTS. Applies to: SQL Server 2016 (13.x) and later versions. Conditionally drops the index only if it already exists. index_name. The name of the index to be dropped. database_name. The name of the database. schema_name
10 Μαρ 2015 · An index scan means that all the leaf-level of the index was searched to find the information for the query: When the index is a clustered index, this is the same as scanning the entire table. With only a few exceptions, this isn’t good; we need to try to turn scans into seeks, which means retrieving the data by just using the index tree.
However, you can use the IF EXISTS option to conditionally drop the index and avoid the error. Note that the IF EXISTS option has been available since SQL Server 2016 (13.x). The DROP INDEX statement does not remove indexes created by PRIMARY KEY or UNIQUE constraints.
What is the difference between and index seek and an index scan? Which performs better? How does SQL choose one over the other? I realise this is 3 questions but I think answering the first one will explain the others. sql-server-2005. performance. index. execution-plan. Share. Improve this question. edited May 20, 2013 at 8:04. Yasir Arsanukayev.
23 Μαρ 2019 · What is the difference between a scan and a seek? A scan returns the entire table or index. A seek efficiently returns rows from one or more ranges of an index based on a predicate. For example, consider the following query: select OrderDate from Orders where OrderKey = 2 Scan
11 Μαρ 2011 · An index scan or table scan is when SQL Server has to scan the data or index pages to find the appropriate records. A scan is the opposite of a seek, where a seek uses the index to pinpoint the records that are needed to satisfy the query.
