for all 16, list system tables # db2 list tables for system 17, list user tables # db2 list tables for user 18. list specific user tables # db2 list tables for schema [user] 1 9. Create a new table (t1) with the same structure as a table (t2) in the database) # db2 create table t1 like t2 20. import data from one tabl
DB2 obtains detailed information about the current user table, field, index, and so on. db2 current user
Obtain detailed information about all tables, fields, and indexes.
SELECT d. name tbName, COALESCE (d. remarks, '') tbDesc,. name columnName,. coltype columnType, decode (. nulls, 'y', '1', '0') notNull, decode (. identity, 'y', '1', '0') auto,. longlength width,. scale precision, COALESCE (. remarks,
Label:Connect reset should terminate the database connection with a commit action terminate should be able to terminate this client-initiated process and release resources Terminate is a command, in addition to disconnecting, it also terminates the CLP (command line processor) background process, which is the common db2bp.connect reset is the SQL statement quit Exit CLP, but the database connection is constantly open connect reset disconnects the database but does not exit the CLPterminate
During the installation and JDBC development of DB2, you may encounter some common problems and make a record to be noted:
1. License
Whether the DB2 version is genuine or not depends on the license, but there is no prompt during the installation process. License installation:
Db2licm-A [path]/db2ese. Lic
If the license is incorrect, the biggest impact is that the database cannot provide services to servers
AUTOMATIC. This saves a lot of time for manual adjustment.
CPU Factors
The CPU factor is first concerned with the analysis and optimization of the access plan by the DB2 OPTIMIZER. Generally, an SQL statement will be parsed first during execution, then semantic analysis is performed, and then the SQL statement is rewritten, the optimizer performs cost-based analysis on the overwritten SQL statements and selects the most effective access plan. Finally
, describes various methods for installing the IBM_DB driver, and uses the Rails migration of DB2.
Introduction
Ruby on Rails was released in 2004 and has now quickly become one of the most popular frameworks in Web application development. This open-source project, also known as Rails or RoR, adopts the Model-View-Controller (MVC) architecture and Ruby object-oriented scripting language, and follows some simple principles, for example, "convention ov
of parallelism on multiprocessor machines. With two new features in V8 load, they are particularly useful for the replacement of load as an insert, with two features: loading from the cursor and loading from the calling layer interface (CLI) application. Loading from a cursor This method can be used in the application's program code (via the Db2load API) or for DB2 scripts. Here is an example of the latter
/errors/errorreport.xml
CALXDB_DECOMP_XML_FROM_QUERY(
'ABC','SALES',
'SELECTDOCID,SALESDOCFROMABC.SALESTAB',
0,0,0,NULL,NULL,1,
:hnumInput,:hnumDecomposed,:herrorreportBuf);
Note: XDA = stores XML documents without inline objects in the basic table.
CLPPLUS vs SQL * Plus
DB2 has a tool similar to Oracle SQL * Plus called CLPPlus. If you know how to use SQL * Plus, you will certainly use CLPPlus.
PL/SQL in
provides access to database objects.DDL: Data definition language, creating, modifying, and deleting database objects.DML: A data manipulation language used to insert, update, and delete data.
What are the 115.DCL permissions?CONTROL permission: If a user creates an object, the user is able to access the object completely.The GRANT statement grants permissions to the user.The REVOKE statement revokes the permissions of a user. What are the 116.DDL?CREATEDECLAREAlterDROPWaitWhat are th
database name is rdb, the local connection string is jdbc: db2: rdb (of course, rdb must be in the default DB2 instance), and the remote connection string is jdbc: db2: // 192.168.1.10/50000: rdb (192.168.1.10 indicates the IP address of the database server, and 50000 indicates the port number of the DB2 Connection Se
completedsuccessfully.$ DB2 "UPDATE student set name= ' gu ' where age=1 'db21034e the command is processed as an SQL statement because it is not aValid command line Processor command. During SQL Processing It returned:sql0911n the current transaction have been rolled back because of a deadlockOrTimeout. Reason code "68". sqlstate=40001$ DB2 "Delete from student
or in the application.
DB2's jdbc type 4 driver is called a universal driver and implemented in Java only. This driver also supports SQLJ.
Currently, no JDBC driver for TYPE 1 is provided by IBM.
The packages of these types of drivers are: db2 driver type jcc. jar and sqlj.zip files, sqllibbindb2jcct2. dll (this file is required by type2 ).
Use
When connecting DB2
type. because there may be problems with the optimization tool processing "or" logic, try to rewrite it in other ways. 8. make sure that the data distribution and other statistics in the processed table are correct and reflect the current situation 9. try to replace union10with Union all. Consider hard encoding or host variable 11. reduce DB2 SQL requests as much as possible 12. try to rewrite the interval predicate to between predicate 13. consider
. on/db2sys/db2inst1/xxx Replace existing redirect without rolling forward The command to change the container and data file path on top of the duplicate is OK. After the path change is complete, restore continue:>DB2 restore DB XXX Continuedb20000i the RESTORE DATABASE command completed successfully.Change archive path GT;DB2 update db cfg for XXX using LOGARCHMETH1 disk:/db2sys/db2log/xxxRestart the datab
the remote connection is jdbc: product_name: // host_name/port _ number: database_name.
That is, if my database name is rdb, the local connection string is jdbc: db2: rdb (of course, rdb must be in the default DB2 instance), and the remote connection string is jdbc: db2: // 192.168.1.10/50000: rdb (192.168.1.10 indicates the IP address of the database server, an
: product_name: database_name. The format of the remote connection is jdbc: product_name: // host_name/port _ number: database_name. That is, if my database name is rdb, the local connection string is jdbc: db2: rdb (of course, rdb must be in the default DB2 instance), and the remote connection string is jdbc: db2: // 192.168.1.10/50000: rdb (192.168.1.10 indicat
COMPRESSIONPCTPAGESSAVED
IDX_COL1T1Y-1
In the preceding statement, a table T1 is created and row compression is enabled for the table. When the index idx_col1 is created, the index compression is automatically started because the base table is compressed. The third sentence of the above Code is to verify that the index idx_col1 does enable compression, and because no statistics are collected, the current compression ratio is-1. When we Inse
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