what is table index

Dbms_stats Import and Export schema-level statistics are used in Oracle databases using the CBO optimizer mode. statistics are an important basis for CBO to generate the best execution plan. These statistics usually include column-level, table-level,

Get DDL metadata SQL comes from the get_ddl function in the dbms_metadata Package of metalkink. Its usage is as follows: -- GET_DDL: Return the metadata for a single object as DDL. -- This inte *** ce is meant for casual browsing (e.g ., from

Oracle single-instance database migration to the OracleRAC environment-data export and import system environment: Operating System: RedHatEL55Oracle: Oracle11.2.0.1.0 cluster software: OracleGI11.2.0.1.0 this case uses Oracle single-instance

1. HashMap Key points: 1.1 Basic data structure :Using the combination of array + list/balanced binary search tree , all key-value pairs are stored in entry form (one key-value pair per put, one entry). An array of:entry arrays, with hash

Reprinted: http://wiki.jikexueyuan.com/project/java-collection/hashtable.htmlOverview Like hashmap, hashtable is also a hash that stores key-value pairs. Hashtable is defined in Java: public class Hashtable extends Dictionary implements

In protected mode, the segment register consists of a 16-bit selector and a 64-bit segment descriptor register.Segment descriptor register: storage segment descriptorSelector: Index of the storage segment descriptor PS: each segment register in the

Applies: Oracle Server-Enterprise Edition-version 11.2.0.3 to 11.2.0.3 [release 11.2]Information in this document applies to any platform.Symptoms -11.2 database with partitioned objects: Select partitioned, count (*) from dba_tables group by

Author: skate Time: 2010-08-31   The following error occurs when testing the speed of exp and expdp: ORA-39095: dumped file space exhausted: unable to allocate 4096 bytesThe job "sys". "sys_export_table_01" was stopped at 13:50:54 due to a fatal

-- 1. What file does SQL consist? /* Answer: SQL is composed of data files and log files */ -- 2. What are the two types of SQL data files? What are the extensions? How many can there be? /* Answer: SQL data files are divided into primary and

Import java. Io. file;Import java. Io. fileinputstream;Import java. Io. filenotfoundexception;Import java. Io. ioexception;Import java. util. arraylist;Import java. util. List; Import org. Apache. log4j. Logger;Import org. Apache. Poi. hssf.

1. Online segment shrink recycles idle space that uses fragments below the high water level line in the Oracle database segment. Segment shrink has the following benefits: 1. compressed data will lead to better cache utilization, resulting in better

Translator's note:Original article address:Http://www.linuxforums.org/articles/understanding-elf-using-readelf-and-objdump_125.htmlThis is the first time I have translated a technical article. There may be some typos, especially when some statements

MySQL experience 9-USER and data security 1. You can use the create user syntax to add one or more users and set the corresponding password. Syntax format: create user user [identified BY [PASSWORD] 'Password'] [, user [identified by [password]

The examples in this article describe how Python implements simple HTML table parsing. Share to everyone for your reference. The specific analysis is as follows: Rely on libxml2dom here to make sure to install first! Import into your footsteps and

Main content of this article:1. Basic Concepts: physical memory, virtual memory, physical address, virtual address, logical address, page directory, and page table2. Windows Memory Management3. CPU Memory Management4. CPU page-Based Memory

What is the principle of database indexing? The management of the MIS system for small and medium-sized enterprises is basically composed of two parts: one is the visual operation at the front end, and the other is the database management at the

An index is a special file (an index on an InnoDB data table is an integral part of a tablespace) that contains reference pointers to all records in the data table. Note: [1]Indexing is not omnipotent! Indexing speeds up data retrieval, but slows

Note: This article is not to give you a case, but to explain the optimization method. The Ancients cloud: it is better to teach people to fish than to teach people to fish. Here we will talk about how to fish. The SQL optimization mentioned here is

Impdp experience ORA-39029, ORA-31671, ORA-06512, impdpora-39029[Oracle @ rac1 ~] $ Impdp \ '/as sysdba \' directory = expdp dumpfile = wxlun0402.dmp logfile = wxlun0402.impdplog REMAP_TABLESPACE = wxlun: wxlun_DATA REMAP_SCHEMA = wxlun:

Android memory optimization: ArrayMap Generally, when we use key-value to store data, we can use HashMap code at will. When the data volume is small, we can also, when the number is large, if it is on a PC, we can also say that, but if you are using