pentaho insert update performance

INSERT operation executed with multiple statements This improves the performance because the index cache is refreshed to the disk only once after all INSERT statements are completed. Generally, the number of INSERT statements is the index cache refresh. If you can use one statement to

';For ($i =0 $i $k 1 = rand (10000,300000);$k 2 = rand (0,3);$k 3 = rand (1,100000);mysql_query ("INSERT into $table (Key1,key2,key3) VALUES ('") $k 1. "', '". $k 2 "', '". $k 3. "", $db);}?> Description: Create 1000000 (100W) record with data size of 16.2 MB 3, the test parameter type is the case of the digital type The code is as follows Copy Code mysql> Update tes

especially useful for multi-row insertions. The VALUES () function is only in the INSERT ... The UPDATE statement makes sense, and returns NULLat other times. Example: INSERT into table (a,b,c) VALUES (4,5,6) On DUPLICATE KEY UPDATE c=values (a) +values (b); This statement works the same as the following two stateme

() function is only in the insert ... is meaningful in the UPDATE statement and returns null at other times. Example: mysql> INSERT into table (a,b,c) VALUES (1,2,3), (4,5,6) -> on DUPLICATE KEY UPDATE c=values (a) +values (b); This statement acts the same as the following two statements: mysql>

-volume data insertions occur when data is imported from the old database, but this kind of import is usually only once, so it is not too serious, other such as the import of data from the uploaded CSV file needs to see the specific business logic, the more common is to use Try/catch to insert, the failure of the data display , let the user confirm the overwrite, and then update. 1) If you can ensure that

Oracle uses merge to update or insert data (Summary) under Java code summary. Using merge is much faster than traditional first judgment and then selecting insert or update. 1) The main function is to UPDATE and insert data to the

For the insertion and update of massive data, ADO. NET is indeed inferior to JDBC, and JDBC has a unified model for batch operations.Very convenient:Preparedstatement PS = conn. preparestatement ("insert or update arg1, args2 ....");Then you canFor (INT I = 0; I PS. setxxx (realarg );.....PS. addbatch ();If (I % 500 = 0) {// assume that five hundred entries are s

Http://blog.csdn.net/axman/article/details/2200840 For the insertion and update of massive data, ADO. NET is indeed inferior to JDBC, and JDBC has a unified model for batch operations.Very convenient:Preparedstatement PS = conn. preparestatement ("insert or update arg1, args2 ....");Then you canFor (INT I = 0; I PS. setxxx (realarg );.....PS. addbatch ();If (I %

' (' id ', ' table_na Me ', ' action ') VALUES (NULL, ' replace_into ', ' insert_after '); CREATE TRIGGER ' Update_after_trigger ' after update on ' Replace_into ' for each ROW insert INTO ' trigger_log ' (' id ', ' table_na Me ', ' action ') VALUES (NULL, ' replace_into ', ' update_after '); CREATE TRIGGER ' Delete_after_trigger ' after delete on ' Replace_into ' for each ROW

Oracle DML Statement (insert, update, delete) rollback Estimation 1. Introduction to Oracle dml SQL rollback Logic Database transactions consist of one or more DML (insert, update, delete) SQL statements. We know that the Oracle database uses the Undo tablespace to store transaction rollback information during DML ope

When mysql processes a unique index, it updates the index. If it does not exist, it should be very common to insert the index. There are many similar articles on the Internet, today I will talk about the problems and methods that may occur when this unique index is a unique index for multiple columns. Method 1: use? INSERTINTO? ON... DUPLICATEKEYUPDATE...: The table is created as follows: C When mysql processes a unique index, it updates the index. If

the specified property and creates it if the key does not exist. $set modifier: A value that specifies a key and creates it if it does not exist. $push: Array modifier, if the specified key exists, adds an element to the end of the existing array, and the key does not exist, a new array is created. 3, Upsert operation The Upsert operation has saveorupdate functionality, and if no document meets the update criteria, create a new document bas

property and creates it if the key does not exist. $set modifier: A value that specifies a key and creates it if it does not exist. $push: Array modifier, if the specified key exists, adds an element to the end of the existing array, and the key does not exist, a new array is created. 3, Upsert operation The Upsert operation has saveorupdate functionality, and if no document meets the update criteria, create a new document based on the

performance improvement, but rather slower than not using batch, of course, this may be related to the implementation of the specific JDBC driver. The attachment is my test code that can be used to run on my own computer. The main thing to do when performing bulk inserts is to automatically commit the cancellation, so that it doesn't matter whether the batch syntax is in JDBC or not. Java code Conn.setautocommit (false) Second, the JDBC batch