![]() ![]() You can remove this RID lookup by including Column1 in the nonclustered primary key, or by changing the primary key from nonclustered to clustered. If it is not changing, a redundant nonclustered index update can be avoided. The RID lookup is needed for the query processor to check if the value of Column1 is being changed. By touching the same resources in reverse order, multiple concurrent executions of the same plan can deadlock. The update side of the plan accesses the base table first, then the nonclustered index. The reading side of the plan accesses the nonclustered index first, then the base table. This is a well-known pattern that often results in a conversion deadlock under high concurrency. The base table appears to be a heap, and the update plan will likely feature an RID lookup: That said, unless the question is missing some detail, you will still have an update statement that is prone to deadlock in another way. The page granularity explains why operations on two different id values can deadlock. You can avoid this specific deadlock by ensuring page-level shared locks are not taken on the same access method after the UPDLOCK statement (row-level shared locks would be ok). The lifetime of that lock is the same as the IU component (the life of the transaction here). Although shared locks are usually released very quickly under the read committed isolation level, that does not occur when the shared lock is merged into a combination lock like SIU. The existing IU page lock is converted to SIU. The SIU lock occurs because somewhere between selecting the row in question with the UPDLOCK hint (which takes IX at the object level, IU at the page level, and U at the row level), a statement in the transaction is acquiring a shared ( S) page-level lock on the nonclustered primary key index structure. The particular issue here is that (4) IX is not compatible with (1) SIU, whereas it is compatible with the more usual IU lock seen in this situation. We have a primary key nonclustered index on column Id. IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF,ĪLLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90 PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, Here is the index we have which is one of the culprits in the deadlock: CREATE NONCLUSTERED INDEX ON. One thing is for sure: records which are getting updated in these 2 procs are different. The methods in those wcf services are updating the same table inside different stored procedures. Involved tables are "volatile" tables, which means contents can vary from empty to very large at run time, so data changing/moving all the time.We have 2 different wcf services which get invoked by a windows service. While trying to get together information about deadlocks I came across this link which asks a question regarding a trace: Interpretation of a column in SQL Server profile trace The answer dealt w.Statistics of those tables are being updated regularly thru ATM of DBACockpit.Involved tables reported in the deadlock messages are custom tables (Z tables).$SYBASE/$SYBASE_ASE/install/.log for Unix, %SYBASE%\%SYBASE_ASE%\install\.log for Windows platforms.Therefore they end up both waiting for the other process. ![]() Same Deadlock errors also reported in the ASE error log. This occurs when two Sql Server processes are accessing the same resources, but in a different order.Please re-run your commaī ***LOG BYO=> deadlock aborts transaction ī SQL code: 1205, SQL text: Your server command (family id #0, process id #625) encountered a deadlock sit From related developper trace you'll find the complete SQL statement :Ĭ ERROR: -1 in function StartSelect (execute) Ĭ (1205) Your server command (family idĬ #0, process id #625) encountered a deadlock situation.xml file in SQL Server Management Studio Figure 3: Double click to get XML report. If you extracted your deadlock using Extended Events you can double click on the xmlreport line in the event details which will open the xml description as an. Please re-run your comma /bas/753_REL/src/dbs/syb/dbsyb.c# 50649]ĭB C1nd. xml and open it in SSMS Figure 2: Deadlock Graph as XML in SSMS. SQL error "SQL code: 0" occurred while accessing table "ZXXXX".ĭB C1(1205) Your server command (family id ĭB C1 #0, process id #625) encountered a deadlock situation. Since database migration to SAP ASE a lot of deadlock errors are being reported in SM21 with ST22 dump like this:. ![]()
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