Monday, October 11, 2010

Informix easy to understand and explain the usage of common commands

Informix common usage and description commands:

Syntax oninit [-s] [-i] [-p] [-y]

oninit 顥?顥?顥?system from off-line mode into on-line mode

oninit-s 顥?system from off-line mode into a quiescent mode

oninit-i 顥?initialization system

oninit-p 顥?in shared memory initialization, do not search, delete the temporary table

oninit-y 顥?automatically answer yes to the prompt

oninit-v option to join the show oninit process

oninit - type this command will be made available to help

oninit command used to change the system's operating mode. One-i option is used to initialize the system root dbspace. Note, root-dbspace Once initialized, the equivalent to the entire database system is initialized.

If users want to start automatically when the computer automatically starts the dynamic server system, the stage in the system files (in many UNIX systems for the / etc / rc) to add oninit command (without any options).

onmode command

Syntax: onmode [-k] [-m] [-s] [-u] [-y]

onmode-k 顥?implementation of the immediate shutdown, the system becomes off-line mode

onmode-m 顥?into the system from the quiescent mode of on-line mode

onmode-s 顥?implement graceful shutdown

onmode-u 顥?implementation of the immediate shutdwon

onmode-y 顥?顥?顥?automatically answer yes to the prompt

onmode command also used to change the active server mode of operation. In addition to these options outside, onmode many and change the operating mode of the independent option.

Command to create the data space using onspaces

Syntax: onspaces-c [-b] [-d] [-z] [-m] [-o] [-p] [-s] [-t]

-C create blobspace or dbspace

-B blobspace blobspace Name

-D dbspace 顥?顥?dbspace name

-G page size 顥?blobpages size

-M mirror 顥?顥?mirrored device set of full path name and offset (KB)

-O offset 顥?顥?offset (KB)

-P pathname 顥?chunk equipment, the full path name

-S size 顥?顥?顥?顥?dbspace size (KB)

-T 顥?顥?顥?顥?顥?顥?create a temporary dbspace

onspaces command is used to create the data space, temporary space and the blob of data storage space (blobspace). Type onspaces - get the command-line help. Use onstat-D or onstat-d to see the system's important information on the data space. Including: chunk of the state, idle, read and write the number in each chunk. The system may include a number of system space, especially when the data slice, we suggest you can use the command line to create the data space.

Can use the following command to create data space:

onspaces-c-d datadbs1-o 0-p / dev/rrvol3-s 60000

Can create temporary data in the following space:

onspaces-c-d tempdbs1-t-o 0-p / dev/rrvol5-s 80000

In the system, the temporary data space is very important, usually, a number of temporary data space should be distributed in separate physical devices.

Command to delete the data space using onspaces

Add or remove chunks

Syntax: onspaces-a-d [-m] [-o] [-p]

-A spacename 顥?顥?顥?new chunk to dbspace

-M pathname 顥?顥?顥?顥?mirror device the full path name and offset (KB)

-O offset 顥?顥?顥?顥?offset of the main equipment (KB)

-P pathname 顥?顥?顥?chunk equipment, the full path name

-S size 顥?顥?顥?顥?顥?顥?chunk size

-D spacename 顥?顥?顥?delete chunk

-O offset 顥?顥?顥?顥?chunk offset equipment (KB)

onspaces not only create a data space can also delete the data space, temporary data storage space or data space blob. In the deleted data space, we must first guarantee that it is useless, that the data is no database or table space.

For delete data space, type the following command: onspaces-d dbspace_name / blobspace_name

Data space first by a chunk (first chunk) form, if the space is used up, the user must append chunk in order to improve system performance, user data space is allocated for the required chunk size calculation to ensure it can meet future needs, otherwise additional chunk of time with the previous chunk is not necessarily physically adjacent, leading to increased time to read the data. On how to calculate space requirements will be in later chapters. Using onspaces command can increase or delete data space chunk, In addition, use the command can complete the following tasks: boot image, suspend or change the mirror chunk of the state.

For example, you can run the data space increases chunk:

onspaces-a-d datadbs1 -0 60002-p / dev/rrvol3-s 60000

Another example can be used as follows to remove space from the data chunk:

onspaces-d datadbs1-o 60002-p / dev/rrvol3-s 60000

onparams command

Syntax: onparams-a-d-p [-d] [-s] [-l]

-A 顥?顥?顥?顥?new logical logs

-D dbspace dbspace specified log storage

-S size 顥?new logical log size (KB)

-D 顥?顥?顥?顥?delete the logical log

-L logid 顥?delete a specified logical log

-P 顥?顥?顥?顥?change the physical log

-D dbspace dbspace new physical log name stored in

-S size 顥?顥?physical log size (KB)

System initialization automatically created in the root dbspace logical logs and physical logs. In DBMS systems, especially in the OLTP environment, the database operations are very frequent, log a lot of information must be recorded, so users can better distribution of multiple log files on different devices. There is a very simple way: that according to the size required to create the logical logs, and to create a smaller physical log, the system initialization has been completed, then move the physical log other devices. On how to determine the required size of the physical log will detail in later chapters. Using onstat-l command to see all the new logic of the system log are identified as A. The only logical logs after archiving system will actually be used. In order to activate the logical logs are a simple way: the implementation of a "pseudo" file. Specific steps are as follows: the parameter TAPEDEV set / dev / null and then run a ontape-s. Can also perform onbar-F command. As the pseudo-file system information file is not true, it must be timely filed on the real system operation.

Only when the logical log can really useless to remove. Using onstat-l can see all of the free log is marked as F. If the logical log contains transaction rollback or quick recovery necessary information, the logical log can not be deleted. Using onstat-l command can be seen to accept the current transaction log is marked as C. If the logical logs including the final point and that a checkpoint, it is not Pi removed, and only when the record is included in the next checkpoint a log Zhong Bing Jushang after a log has been backed up, Gai log can be deleted. Using onstat-l command to see the last checkpoint record contains the log are marked as L. Users can use onmode-c command to force to write the checkpoint record until the last checkpoint record is written until the required log.

onstat tool

Display Dynamic Server shared memory information

Involving a small amount of disk I / O operations

Will have minimal impact on system performance

Information on the system may provide valuable

Command-line interactive monitoring system

In this chapter will explain the various important onstat options, familiar with their use

onstat command is a very useful tool for real-time monitoring system. The order directly from the shared memory data structures to read the information, the report was state of the system. Onstat command will not normally disk I / O operation, it would not lock system resources, so its system performance to reduce to a minimum. In short, onstat is informix provides an interactive system monitoring tool.

onstat of some commonly used options:

onstat - 顥?顥?顥?顥?all the options listed

onstat-i 顥?顥?顥?顥?set to enter interactive mode

onstat - 顥?顥?顥?顥?display operation mode and the database engine state

onstat-g sub_option option to run more clues

onstat-r; intervals; seconds to repeat options

onstat-g act 顥?顥?display system leads all the activities

onstat-g ath-r 2 display system every two seconds leads all the activities

System Monitoring Interface

sysmaster database is automatically created in the system initialization

Database shared memory structure, including point to the system data dictionary information

Provide instantaneous system performance and status information

SQL interface to provide information about data dictionary

Allows administrators to automate systems management

Used to perform repetitive monitoring tasks

System Monitoring Interface (system Monitoring Interface - SMI) is a SQL-based system tools, users can easily access SMI system information. System initialization, automatically created in the root dbapace sysmaster system database. Sysmaster each system includes a database of most of the tables for the virtual table, pointing to shared memory data structure pointer. SMI can use automatic monitoring system, especially in the implementation of the repeated task.

sysmaster database is read-only, that is not to allow its INSERT UPDATE, or DELETE operation. All users have permission to query the database.

In the system initialization, the user must pay attention to check whether the establishment of a successful sysmaster database. Create sysmaster database information is stored in the message log file (online.log) Please note that as all the DDL statements will be recorded in the log, they must be in the log file to allow sufficient space to ensure that necessary to create sysmaster .

sysmaster database schema recorded in $ INFORMIXDIR / etc / sysmaster.sql file.

oncheck command

Check dynamic server disk data structures

Locate and repair damage to the index and data

With disk I / O operations

Some operations in processing the lock on the table

oncheck command is used to repair a damaged disk index and data pages, the order can also be used to check and print the system's data structure. When using oncheck must be careful, because some options will change the order form plus a shared lock, for example: oncheck-pt

To prevent damage to the system, the system will have all the shared memory data in a consistency check. Once a data page consistency error or if the index appears an error, the system will issue and possible solutions (using oncheck) write message log file, and return isam error code 105.

If you find that consistency of error message, the user should immediately shut down the system message log files according to the prompt to run oncheck. If oncheck run fails, you should try to unload the table and then re-load; if the index was the problem, you should first delete the index and then reconstruction. If all these steps fail, the system only under the original backup file to restore the system.

Extend the following command can provide information: oncheck-pe




dirt executable has stopped working Eliminate


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