truncate in teradata

Oracle has its own unique practices for truncate table operations. It takes almost the same time to truncate dozens of data records and tens of millions of data records, Oracle only updates the data dictionary and does not operate on the actual data. It only needs to pull back the hwm location. Sys @ orcl> Create Table big_table as select * From all_objects; Table created. Sys @ orcl> insert into big_tab

) | 00:00:01 || * 10 | index unique scan | I _IND1 | 1 | 1 (0) | 00:00:01 || 11 | nested loops | 1 | 82 | 1 (0) | 00:00:01 || * 12 | index skip scan | I _LINK1 | 1 | 79 | 0 (0) | 00:00:01 || 13 | table access cluster | USER $ | 1 | 3 | 1 (0) | 00:00:01 || * 14 | index unique scan | I _USER # | 1 | 0 (0) | 00:00:01 |Bytes -----------------------------------------------------------------------------------------------SQL> truncate table xtdwtest;Table tr

How do I differentiate database deletion statements from drop and delete and truncate ?, Droptruncate 1. delete: delete rows in the data table (you can delete a row or delete all rows without deleting the data table) Delete a row: delete from data table name where column name = value; Delete all rows: delete * from data table name 2. drop: delete a data table or database or data table Field Delete database: drop database Name Delete A data table

I suddenly thought of this problem recently and recorded it to consolidate my knowledge. Tables, temporary tables, and table variables are used by many people. truncate Table @ table variables may report errors. I believe many people have encountered them, but there are few people who really think about why, after all, in most cases, most of us only need to use it, and do not need to know why. Moreover, domestic projects are always so tense that ther

We generally think that truncate is an operation that cannot be rolled back, it deletes all the data in the table and resets the identity column. If you do a truncate operation in a transaction, you can roll back. Conversely, it does not recover data from the log file file. It does not record the deleted data in the log file, it only records the cell allocation of the data page in the log. The following e

Drop deletes the entire table's datasheet structure. Transaction cannot be rolled back.? 1 drop table test; Truncate deletes all the data in the table and does not line up. And the transaction cannot be rolled back.? 1 TRUNCATE TABLE test; Delete is for each row of data. Transactions can be rolled back.? 1 Delete from test where id=1;

This is because the table with the truncate operation is still executing, and no commit is finished, at which point you can query V$locked_object to get which user's transaction is operating this table. Experimental SimulationFirst, use the Scott user to enter the database and do the following for the existing table T1:sql> Delete from T1 where name like '%c% ';23308 rows deleted.Note that a commit was not executed here.Then, in another session, the d

Recently released to the market version of the frequent occurrence of database table corruption, the specific phenomenon is that the Select Table hint table does not exist, but to view the data file, the corresponding table of IBD and frm files are in.Through the statistics of multiple failures, found several frequently damaged tables, in the analysis process, found that these data tables used truncate to clear the data, so suspect is the

scenarios occurs: If auto-grow is set, the physical log file size is increased by the growth percentage/value, which is why our transaction log files often become very large. SQL Server throws a 9002 error if no automatic growth is set or if the disk that stores the transaction log files does not have free space. Note: If a database has more than one transaction log file (LDF), no other transaction log files will be used unless the first transaction log file has no free space.

When truncate an Oracle table, an error occurs:ORA-00604: A recursive SQL Level 1 error occurredORA-00904: "CURRENT_SCN": Invalid identifierThe analysis is due to the fact that a materialized view is built on the table:Select log_owner,log_table from All_mview_logs;Log_owner log_table----------------　---------------Newsadmin Mlog$_ann_basinfoAfter deleting the materialized view Log table, TRUNCATE returns t

Define a self-increment column, use Delete, and then insert the data, the self-increment column is still incremented by the maximum value before deletion; If you use truncate and then insert the data, the self-increment column increments from the beginningScript one (using delete):CREATE table #test (codes int identity,valuess int)Insert into #test (valuess) Select 1SELECT * FROM #test----------------Delete from #test------------------Insert into #tes

The TRUNCATE command clears all records in the Table in mysql and resets the table ID. Next I will introduce the usage and instance of TRUNCATE. Truncate table deletes all rows in the TABLE, but does not record the deletion of a single row. SyntaxTruncate table name;ParametersName (the name of the table to be truncated or the name of the table to delete all its r

How to do the truncate operation for a primary table associated with a foreign key The primary and Foreign keys are mandatory associations between two tables provided by the database. They can also be implemented at the application layer. Advantages Disadvantages Primary and Foreign keys implemented by the database Guaranteed by the database layer mechanism, no additional application implementation is required Strong Ass

High_value------------------------- ------------------------- ------------------ ------------------------------ -----------P_andy P1 1 USERS 10P_andy P2 2 USERS 20P_andy P3 3 USERS 30P_andy P4 4 USERS 40--Inserting dataSql>BeginFor I in 1.. The LoopINSERT into P_andy values (i, ' andyi ');End Loop;CommitEnd/PL/SQL procedure successfully completed. 二、一次 truncate or drop multiple partitions (This shows that only the

Differences among truncate, drop, and delete: 1. truncate and drop belong to DDL (DataDefinitionLanguage Data Definition Language). delete belongs to DML (DataManipulationLanguage data operation language) 2. From the perspective of table structure, truncate and delete only delete data, but do not delete the table structure drop delete data and table knot Differe

There are two common methods to clear the content of a mysqll table: delete and truncate. The delete statement without the where parameter can delete all contents in the mysql table. You can also use truncatetable to clear all contents in the mysql table. In terms of efficiency, truncate is faster than delete, but after truncate is deleted, mysql logs are not rec

Myth #19: TRUNCATE TABLE operations are not logged to the log Error Actions in the user table are recorded in the log. The only operation in SQL Server that is not logged to the log is row versioning in tempdb. The Truncate table statement deletes all data from the entire table. But the way to delete is not to delete a row, but to release the data page that makes up the table, the process of releasing

In the actual working environment, if you Truncate several data dictionary tables in the database during the operation, the database will no longer be available. In the actual working environment, if you Truncate several data dictionary tables in the database during the operation, the database will no longer be available. In the actual working environment, if you T