How do I narrow my search results?
After you submit your search query:
- On the Refine Search results page, select one or more categories of products or services from the left sidebar.
- Then for a category with search results, click Select to choose your product and release filters, and then click OK.
For search queries that contain multiple words, surround the query with quotes, and then resubmit your query. Example: "database cloud service"
How do I find the documentation for my product or service?
From the home page, click the technology categories for your products or services. If you do not know which category to pick, try the following features:
- Click the Find a product tab and search for your product or service.
- Click Browse All Products & Services at the bottom of the home page to view an alphabetical listing of products and services.
- Apple Safari: Version 6
- Google Chrome: Version 29 and later
- Mozilla Firefox: Version 24 and later
- Microsoft Internet Explorer: Version 9 and later
DISASSOCIATE STATISTICS → Purpose Use the DISASSOCIATE STATISTICS statement to disassociate default statistics or a … statistics type from columns, standalone functions, packages, types, domain indexes, or indextypes. See Also … : ASSOCIATE STATISTICS for more information on statistics type associations Prerequisites To issue
Optimizer Statistics → Optimizer statistics are a collection of data that describe details about the database and the … objects in the database. The statistics provide a statistically correct picture of data storage and … distribution usable by the optimizer when evaluating access paths. Optimizer statistics include the … following: Table statistics
ASSOCIATE STATISTICS → Purpose Use the ASSOCIATE STATISTICS statement to associate a statistics type (or default … statistics) containing functions relevant to statistics collection, selectivity, or cost with one or more … current statistics type associations, query the USER_ASSOCIATIONS data dictionary view. If you analyze
STATISTICS → Default: ALWAYS Specifies what is done with the database optimizer statistics at import time. The … options are: ALWAYS Always import database optimizer statistics regardless of whether they are … questionable. NONE Do not import or recalculate the database optimizer statistics. SAFE Import database … optimizer statistics
STATISTICS → Default: ESTIMATE Specifies the type of database optimizer statistics to generate when the exported … precalculated statistics in the export file, and also the ANALYZE statements to regenerate the … statistics. However, the precalculated optimizer statistics will not be used at export time if a table has … columns
Automatically Collecting Statistics on Tables → The PL/SQL package DBMS_STATS lets you generate and manage statistics for cost-based optimization … . You can use this package to gather, modify, view, export, import, and delete statistics. You can … also use this package to identify or name statistics that have been gathered. Formerly, you enabled … DBMS_STATS to automatically
13.5.8 Handling Missing Statistics → When Oracle Database encounters a table with missing statistics, by default the database … dynamically gathers the statistics needed by the optimizer. However, for certain types of tables, including … remote tables and external tables, Oracle Database does not gather dynamic statistics. In these cases … and also when dynamic statistics
7.4.2 Log Buffer Statistics → $SYSSTAT. Use the following query to monitor these statistics over a period while your application is
5.1.1 Database Statistics → Database statistics provide information on the type of load on the database and the internal and … external resources used by the database. This section describes some of the more important statistics … . 18.104.22.168 Wait Events Wait events are statistics that are incremented by a server process or thread … I/O: wait for blocks to
17.1.1 Statistics Analysis → The optimizer relies on object statistics to generate execution plans. If these statistics are … statistics, and produces two types of output: Recommendations to gather relevant statistics for … objects with stale or no statistics Because optimizer statistics are automatically collected
10.2.4 Additional Statistics → There are several statistics that can indicate performance problems that do not have corresponding … obtain a read-consistent image of the table. Compare the following V$SYSSTAT statistics to … or updated. This is called delayed block cleanout. The ratio of the following V$SYSSTAT statistics … reorganize tables 10.2.4.4 Parse-Related
13.4 System Statistics → System statistics describe the system's hardware characteristics, such as I/O and CPU performance … I/O and CPU resources required for each query. System statistics enable the query optimizer to more … plan. When Oracle Database gathers system statistics, it analyzes system activity in a specified time … period (workload statistics)
13.4.2 Noworkload Statistics → Noworkload statistics consist of I/O transfer speed, I/O seek time, and CPU speed ( cpuspeednw … ). The major difference between workload statistics and noworkload statistics lies in the gathering … method. Noworkload statistics gather data by submitting random reads against all data files, while … workload statistics
13.5.2 Managing Extended Statistics → DBMS_STATS enables you to collect extended statistics, which are statistics that can improve … following types of extended statistics: Column group statistics This type of extended statistics … statement. See \"Managing Column Group Statistics\". Expression statistics
13.6 Controlling Dynamic Statistics → By default, Oracle Database automatically gathers dynamic statistics when optimizer statistics are … missing or need augmentation. To obtain the statistics, the database uses recursive SQL during … parsing to scan a small random sample of table blocks. Note: Dynamic statistics were called dynamic … sampling in
5.1.3 Interpreting Statistics → statistics. One way to ensure that your interpretation of the statistics is correct is to perform … , because foreground activities are tunable, it is better to first analyze the statistics from … foreground activities before analyzing the statistics from background activities. Some pitfalls are … timed statistics
13 Managing Optimizer Statistics → This chapter explains why statistics are important for the query optimizer and how to gather and … use optimizer statistics with the DBMS_STATS package. The chapter contains the following sections … : Overview of Optimizer Statistics Managing Automatic Optimizer Statistics Collection Gathering … Statistics
13.3 Gathering Statistics Manually → If you do not use automatic optimizer statistics collection, then you must run DBMS_STATS to … manually collect statistics in all schemas, including system schemas. If the database content changes … regularly, then you must also gather statistics regularly to ensure that the statistics accurately … Statistics
13.6.2 Dynamic Statistics Concepts → Dynamic statistics are enabled in the database by default. You can disable the feature by setting … the initialization parameter OPTIMIZER_DYNAMIC_SAMPLING=0. 22.214.171.124 Dynamic Statistics Levels The … dynamic statistics level controls both when the database gathers dynamic statistics, and the size of … the sample