truncate in teradata

Tags: file io2014artfor cti Select--' select * from ', Table_schema, '. ', table_name, ' into outfile '/work/opdir/repair '--concat (' UNION All-- Select COUNT (1) as Count_, ' ', Table_schema, '. ', table_name, ' as Tbname from ', Table_schema, '. ', TABLE_NAME, ' )--As Sql_concat (' select * from ', Table_schema, '. ", TABLE_NAME, ' into outfile '/work/opdir/repair/', Table_schema, '. ', table_name, '. TSV '; Truncate table ', Table_schema, '. ', ta

Differences:1. truncate and delete: delete only data. Do not delete the table structure (Definition)The drop statement deletes the constraints (constrain), triggers (triggers), and indexes that the table structure is dependent on.Stored Procedures/functions will be retained, but will become invalid.2. The delete statement is dml, which is placed in the rollback segement and takes effect only after the transaction is committed. If a corresponding trigg

I. first introduce the basic usage of file, seek, and truncate: Seek (offset, where): Where = 0 moves from the starting position, 1 moves from the current position, and 2 moves from the ending position. When there is a line change, it will be truncated by a line break. Seek () has no return value, so the value is none. Tell (): the current location of the file, that is, the location where tell obtains the file pointer, which is affected by seek, Readl

Truncate table nameFast and efficient, because the truncate table function is the same as the DELETE statement without the WHERE clause: both DELETE all rows in the TABLE.However, truncate table is faster than DELETE and uses less system and transaction log resources.The DELETE statement deletes a row at a time and records one row in the transaction log.Truncate

Differences: 1. truncate and delete: delete only data. Do not delete the table structure (Definition) The drop statement deletes the constraints (constrain), triggers (triggers), and indexes that the table structure is dependent on. Stored Procedures/functions will be retained, but will become invalid. 2. The delete statement is DML, which is placed in the rollback segement and takes effect only after the transaction is committed. If a correspon

A table with a self-increment sequence, what are the different results after using delete and truncate?Presumably, using truncate, the records in the table are all cleared, and if you insert data into the table, the data is sorted starting at 1.If you are using Delete, the sorted value of the record is not cleared and it is added at once. Here is a small example, you can refer to------------================

Differences between truncate and delete 1. Delete generates rollback. If a table with a large data volume is deleted, it takes up a lot of rollback segments. truncate is a DDL operation and does not generate rollback, which is faster.Truncate table does not generate rollback information and redo records so it is much faster than Delete. In default, it deallocates all space within t the space allocated by

Note Compared to the DELETE statement, the TRUNCATE TABLE has the following advantages: The transaction log space used is small. The DELETE statement deletes one row at a time and records an entry for each row that is deleted in the transaction log. TRUNCATE table deletes data by releasing the data pages used to store table data, and only records page releases in the transaction log. There are usu

Tags: recover autonumber SQL Server from Run efficiency data ble cannot--Removes all data from the table, automatically numbering zeros.--1.delete from Biao--Removes all data from the table and automatically numbers the zeros.--2.truncate Table Biao--truncate Features:The--1>truncate statement cannot be followed by a where condition (cannot be deleted by conditio

Truncate of big data tables, column deletion, shrink recovery High Level 1. truncate operations on Big Data Tables 1. truncate related tables. truncate first deletes the space records occupied by the table in the data dictionary. 2. Release all data blocks occupied by the table 3. At last, the hwm of the table is minim

This article mainly introduces how to use the truncate () method to operate files in Python. it is the basic knowledge of getting started with Python. For more information, see truncate () the object size. If an optional size parameter exists, the maximum size of the file is truncated. The default size is the current position. The current file location does not change. Note: If the size of a specified file

TRUNCATE TABLE players; Equivalent to delete from players, or delete players from players; Either delete players.* from players;1, truncate speed, false with rollback command, delete will be revoked, and truncate will not.2. Truncate is a DDL statement. As with other DDL, it is implicitly committed and cannot be used w

Differences between drop, delete, and truncate in oracle, In oracle, the drop, delete, and truncate commands can be used to delete tables in the database. Many articles and tutorials on the Internet specifically explain the similarities and differences between them. The following is a simple example:1. Both delete and truncate delete the table content but cannot

This article mainly introduces the use of the Truncate () method of manipulating files in Python, which is the basic knowledge of Python's introductory study, and needs friends to refer to the following The truncate () method truncates the size of the file. If an optional dimension parameter exists, the file is truncated (up to) in size. The size defaults to the current position. The current file location

Today, when cleaning up business-Library data, developers say they can use TRUNCATE table to clean up all data from two tables Both tables have their own ID, all made table partitions, single table 200GB, two tables using SELECT ident_current (') The current self appreciation is 3000012, the two tables are almost identical, except for one or two fields. I executed two SQL statements, truncate all two tab

Tags: rop cat cut Media te Pro for a login SQL caseThe requirement for TRUNCATE permissions in an Oracle document is that a table is required under the currently logged-on user, or the currently logged-on user has the permission to drop any table.However, if the first condition is not met, the permission is too large for a user to satisfy the second condition.Refer to the discussion on the Web, you can use the stored procedure to time.For example, the

To delete data from a table: TRUNCATE TABLE wp_comments; Delete * from wp_comments; The difference between the two methods:Where the table in the truncate operation can be omitted, the * in the delete operation can be omitted. Both of these are emptying the data in the Wp_comments table, but there are also differences, as follows:Truncate is the overall deletion (faster), delete is deleted one by

The following test begins with the new features of Oracle 11g truncate enhancements and delay segment space creation. Oracle starting with 11g, when a user creates an empty table, the segment and space are not allocated first, only when the first row of data is inserted into the table. this solves the many tables that are empty but occupy a lot of disk space. Test 11g delay segment creation and truncateThere is a new table under the userSql> Select *

In short, the table id cleared with truncate will be from the new record, while the table cleared with delete will not continue with the original data record from the new record. Of course, the id here is self-increasing========================================================== ========================================================== ==================This article demonstrates how to use the truncate comm

Many systems only perform a flag when performing the delete operation, and do not perform operations that are as expensive as setting the disk to 0. The same is true for truncate. Only the segment header and I-node tables are changed. Truncate generates Redo, which is generated by modifying the data dictionary, rather than deleting the data. Truncate reduces hwm,