Category：MsSql
-
Time：2020-11-25
select c.unique_ The number of compilations and recompilations that compiles as will benefit from the missing index group, c.user_ The number of possible uses of lookups after indexing, c.user_ The number of scans that can be used after the index is created, c. Statement as table name, c.equality_columns, c.inequality_columns,c.included_columns, c. Name as library name, c.avg_ […]
-
Time：2020-11-25
When a key value pair is passed to a hash function, after the calculation of the hash function, the key value pair will be placed in the appropriate hash buckets according to the results Take a chestnut Let’s assume that the modulus of 10 (% 10) is the hash function. If the key of the […]
-
Time：2020-11-24
DECLARE @tbl nvarchar(265) SELECT @tbl = ” SELECT o.name,i.index_id, i.name, i.type_desc, substring(ikey.cols, 3, len(ikey.cols))AS key_cols, substring(inc.cols, 3, len(inc.cols)) ASincluded_cols, stats_date(o.object_id, i.index_id) ASstats_date, i.filter_definition FROM sys.objects o JOIN sys.indexes i ON i.object_id = o.object_id CROSS APPLY (SELECT ‘, ‘ + c.name + CASE ic.is_descending_key WHEN 1 THEN ‘ DESC’ ELSE ” END FROM sys.index_columns ic JOIN […]
-
Time：2020-11-24
When you need to install SQL server again, if the serial number cannot be found, you can try to retrieve the serial number from the installed instance, because after installing SQL server, the product key is saved in the registry; If the installation package downloaded by MSDN subscription has a built-in serial number, there is […]
-
Time：2020-11-23
In. Net development, we often use SQL server and Microsoft SQL Server is actually quite good, and its developer (developer version) is also free for users to use, but during the installation process, especially when there is no new installation of the previous version, there are often many problems. In this article, I will reproduce […]
-
Time：2020-11-23
1. / * get the path and name of the trace file*/ SELECT d.VALUE || ‘/’ || LOWER (RTRIM (i.INSTANCE, CHR (0))) || ‘_ora_’ || p.spid || ‘.trc’ trace_file_name FROM (SELECT p.spid FROM v$mystat m, v$session s, v$process p WHERE m.statistic# = 1 AND s.SID = m.SID AND p.addr = s.paddr) p, (SELECT t.INSTANCE FROM […]
-
Time：2020-11-22
Original post address:https://www.cnblogs.com/jinanxiaolaohu/p/10030021.html Alter database (transact SQL) compatibility level https://docs.microsoft.com/zh-cn/sql/t-sql/statements/alter-database-transact-sql-compatibility-level?view=sql-server-2017 Applicable objects:SQL Server (from 2008)Azure SQL databaseAzure SQL data warehouseParallel data warehouse Set some database behaviors to match the specifiedSQL server version is compatible. For other alter database options, seeALTER DATABASE (Transact-SQL)。 For more information about syntax conventions, seeTransact SQL syntax conventions。 grammar copy ALTER […]
-
Time：2020-11-22
Direct steps: 1) Create a new database 2) Add several filegroups 3) Return to the General tab and add the database file Do you see the red boxes? The file group created in the previous step is used here. Look at the following path, I put each file on a different disk, and it […]
-
Time：2020-11-21
1. Recover the database from the log –Create test database CREATE DATABASE Db GO — backup the database BACKUP DATABASE Db TO DISK=’c:\db.bak’ WITH FORMAT GO — create test table CREATE TABLE Db.dbo.TB_test(ID int) — delay for 1 second, […]
-
Time：2020-11-21
What we are going to tell you today is the actual operation steps of copying SQL server data into access database. The main structure of tables in copying some data in SQL Server database to access database is the same. Do not use openrowset, because access file and SQL server are not on the same […]
-
Time：2020-11-20
You need to copy the database file and stop the sql service. If you don’t use it offline or separate, it will be slow. As a result, after restarting the service, SQL starts to report an error Unable to load DLL xpstar.dll Or a DLL it references. Reason: 126 (the specified module was not found. […]
-
Time：2020-11-20
What happens in SQL server that causes its execution plan to change from index seek to index scan? The following test, summary and induction are made from several aspects combined with the context of specific scenarios. 1: Implicit conversion causes execution plan to change from index seek to index scan Implicit Conversion will cause index […]
