我有一个死锁报告,告诉我有一个涉及waitresource =“KEY:9:72057632651542528(543066506c7c)”的冲突,我可以看到:
- <keylock hobtid="72057632651542528" dbid="9" objectname="MyDatabase.MySchema.MyTable" indexname="MyPrimaryKeyIndex" id="locka8c6f4100" mode="X" associatedObjectId="72057632651542528">
在< resource-list>内我希望能够找到密钥的实际值(例如,id = 12345).我需要使用什么sql语句来获取该信息?
解决方法
来自@ Kin,@ AaronBertrand和@DBAFromTheCold的答案非常棒,非常有帮助.我在测试期间发现的另一个重要信息是,在查找%% lockres %%时(通过索引查询提示),您需要使用sys.partitions为给定HOBT_ID返回的索引. .此索引并不总是PK或聚簇索引.
例如:
- --Sometimes this does not return the correct results.
- SELECT lockResKey = %%lockres%%,*
- FROM [MyDB].[dbo].[myTable]
- WHERE %%lockres%% = @lockres
- ;
- --But if you add the index query hint,it does return the correct results
- SELECT lockResKey = %%lockres%%,*
- FROM [MyDB].[dbo].[myTable] WITH(NOLOCK INDEX([IX_MyTable_NonClustered_index]))
- WHERE %%lockres%% = @lockres
- ;
这是使用来自每个答案的片段修改的示例脚本.
- declare @keyValue varchar(256);
- SET @keyValue = 'KEY: 5:72057598157127680 (92d211c2a131)' --Output from deadlock graph: process-list/process[waitresource] -- CHANGE HERE !
- ------------------------------------------------------------------------
- --Should not have to change anything below this line:
- declare @lockres nvarchar(255),@hobbitID bigint,@dbid int,@databaseName sysname;
- --.............................................
- --PARSE @keyValue parts:
- SELECT @dbid = LTRIM(SUBSTRING(@keyValue,CHARINDEX(':',@keyValue) + 1,@keyValue,@keyValue) + 1) - (CHARINDEX(':',@keyValue) + 1) ));
- SELECT @hobbitID = convert(bigint,RTRIM(SUBSTRING(@keyValue,@keyValue) + 1) + 1,CHARINDEX('(',@keyValue) - CHARINDEX(':',@keyValue) + 1) - 1)));
- SELECT @lockRes = RTRIM(SUBSTRING(@keyValue,@keyValue) + 0,CHARINDEX(')',@keyValue) - CHARINDEX('(',@keyValue) + 1));
- --.............................................
- --Validate DB name prior to running dynamic sql
- SELECT @databaseName = db_name(@dbid);
- IF not exists(select * from sys.databases d where d.name = @databaseName)
- BEGIN
- RAISERROR(N'Database %s was not found.',16,1,@databaseName);
- RETURN;
- END
- declare @objectName sysname,@indexName sysname,@schemaName sysname;
- declare @ObjectLookupsql as nvarchar(max) = '
- SELECT @objectName = o.name,@indexName = i.name,@schemaName = OBJECT_SCHEMA_NAME(p.object_id,@dbid)
- FROM ' + quotename(@databaseName) + '.sys.partitions p
- JOIN ' + quotename(@databaseName) + '.sys.indexes i ON p.index_id = i.index_id AND p.[object_id] = i.[object_id]
- JOIN ' + quotename(@databaseName)+ '.sys.objects o on o.object_id = i.object_id
- WHERE hobt_id = @hobbitID'
- ;
- --print @ObjectLookupsql
- --Get object and index names
- exec sp_executesql @ObjectLookupsql,N'@dbid int,@objectName sysname OUTPUT,@indexName sysname OUTPUT,@schemaName sysname OUTPUT',@dbid = @dbid,@hobbitID = @hobbitID,@objectName = @objectName output,@indexName = @indexName output,@schemaName = @schemaName output
- ;
- DECLARE @fullObjectName nvarchar(512) = quotename(@databaseName) + '.' + quotename(@schemaName) + '.' + quotename(@objectName);
- SELECT fullObjectName = @fullObjectName,lockIndex = @indexName,lockRes_key = @lockres,hobt_id = @hobbitID,waitresource_keyValue = @keyValue;
- --Validate object name prior to running dynamic sql
- IF OBJECT_iD( @fullObjectName) IS NULL
- BEGIN
- RAISERROR(N'The object "%s" was not found.',@fullObjectName);
- RETURN;
- END
- --Get the row that was blocked
- --NOTE: we use the NOLOCK hint to avoid locking the table when searching by %%lockres%%,which might generate table scans.
- DECLARE @finalResult nvarchar(max) = N'SELECT lockResKey = %%lockres%%,*
- FROM ' + @fullObjectName
- + ISNULL(' WITH(NOLOCK INDEX(' + QUOTENAME(@indexName) + ')) ','')
- + ' WHERE %%lockres%% = @lockres'
- ;
- --print @finalresult
- EXEC sp_executesql @finalResult,N'@lockres nvarchar(255)',@lockres = @lockres;