SQL Scripts for Indexes and Data Dictionary Queries in Oracle and Sample Outputs

1. Retrieve Information About Indexes from Data Dictionary Views 

 This script retrieves information about indexes from the data dictionary views (all_indexes, dba_indexes, or user_indexes). Replace 'YOUR_SCHEMA_NAME' with the name of the schema you want to query. The script returns details about the indexes in the specified schema, such as index name, associated table, uniqueness, status, tablespace, and indexed columns.

SQL Query to Get Tables Which are Not Having Index on Foreign Key(FK) Column

To identify tables in an Oracle database that do not have an index on their foreign key columns, you can use the USER_CONSTRAINTS and USER_INDEXES views. Here's a SQL query to retrieve such information 

SQL Query to Find Out Timezone Information from Oracle Database

Query 1

To view timezone information in an Oracle database, you can use the DBTIMEZONE and SESSIONTIMEZONE functions along with the FROM_TZ and TO_TIMESTAMP_TZ functions. 

Here's a SQL query to achieve this:

SQL scripts for Indexes and Index-Organized Tables (IOTs), along with sample output, description, and SQL queries

1. List the Indexes Associated with an Index-Organized Table 

This script lists the indexes associated with a specific Index-Organized Table (IOT). Replace 'YOUR_IOT_TABLE_NAME' with the name of the IOT for which you want to view the associated indexes. The script queries the all_ind_columns data dictionary view to retrieve index information for the specified IOT.

SQL scripts for index compression in Oracle, along with sample outputs

1. Identify Indexes Using Index Key Compression 

This script identifies indexes using index key compression. It queries the all_indexes data dictionary view to find indexes that have compression enabled (compression = 'ENABLED'). The compress_for column provides information about the compression level, such as "QUERY HIGH," "QUERY LOW," or "ARCHIVE HIGH."

SQL scripts for index performance analysis in Oracle

1. Estimate the Impact of Dropping an Index on Query Performance 

 This script estimates the impact of dropping an index on query performance. Replace with the original query you want to analyze. Execute the script to generate the execution plan for the original query.

SQL scripts for index usage by SQL statements in Oracle

1. Identify SQL Statements Not Using an Existing Index 

This script identifies SQL statements that are not using an existing index. It queries the v$sql view to find statements that do not contain hints for index usage (/*+ INDEX(...) */ or /*+ FULL(...) */). This helps identify potential opportunities for index optimization.

SQL scripts for index monitoring and statistics in Oracle

1. Check the Last Analyzed Date of an Index 

This script checks the last analyzed date of a specific index. Replace 'YOUR_SCHEMA_NAME' and 'YOUR_INDEX_NAME' with the appropriate schema and index names you want to query. The script queries the all_indexes data dictionary view to retrieve the last_analyzed date for the specified index.

SQL scripts for indexes and partitioning in Oracle

1. Identify Indexes on Partitioned Tables or Specific Partitions 

 This script identifies indexes on partitioned tables or specific partitions. Replace 'YOUR_SCHEMA_NAME' and 'YOUR_TABLE_NAME' with the appropriate schema and table names you want to query. The script queries the all_ind_partitions data dictionary view to find indexes associated with partitions of the specified table.

SQL Scripts for Indexes and Constraints in Oracle

1. List Indexes Associated with a Specific Table Constraint 

 This script lists indexes associated with a specific table constraint, such as a primary key or unique constraint. Replace 'YOUR_TABLE_NAME' and 'YOUR_CONSTRAINT_NAME' with the actual table name and constraint name you want to query. The script joins the all_indexes and all_constraints data dictionary views to retrieve information about the indexes linked to the specified constraint.

SQL Scripts for Index Maintenance and Alterations in Oracle:

1. Disable or Enable an Index Temporarily 

 This script disables an index temporarily for maintenance or testing purposes using the ALTER INDEX ... UNUSABLE statement. Replace 'YOUR_INDEX_NAME' with the name of the index you want to disable. Once you have finished your maintenance or testing, you can re-enable the index using the ALTER INDEX ... REBUILD statement.

SQL Script for Index Recommendations and Analysis in Oracle:

1. Generate Index Recommendations using Oracle SQL Tuning Advisor 

 Description: This script generates index recommendations using the Oracle SQL Tuning Advisor for a specific SQL statement. Replace 'SELECT /*+ YOUR_HINTS */ YOUR_COLUMNS FROM YOUR_TABLE WHERE YOUR_CONDITIONS;' with the actual SQL statement you want to tune.

SQL scripts for index statistics and monitoring in Oracle

1. Gather Index Statistics for a Specific Index or All Indexes 

These scripts use the DBMS_STATS package to gather index statistics. The first script gathers statistics for a specific index, where you need to replace 'YOUR_SCHEMA_NAME' and 'YOUR_INDEX_NAME' with the appropriate schema and index names. The second script gathers statistics for all indexes in a schema using the GATHER_SCHEMA_STATS procedure.

Script to Generate Index Rebuild Scripts for Heavily Fragmented Indexes

This script generates index rebuild scripts for heavily fragmented indexes with clustering factors greater than 1000. It uses a PL/SQL block to iterate over the indexes and generates an ALTER INDEX ... REBUILD statement for each index. The generated scripts are displayed using the DBMS_OUTPUT.PUT_LINE function. These advanced scripts provide additional functionality,

Script to Analyze Index Fragmentation and Generate Maintenance Scripts

This script analyzes the fragmentation of indexes with clustering factors greater than 1000 and generates maintenance scripts based on the fragmentation level. It uses a PL/SQL block to iterate over the indexes, and for each index, it determines whether to rebuild it (if clustering factor > 2000) or reorganize it (if clustering factor <= 2000). The generated scripts are displayed using the DBMS_OUTPUT.PUT_LINE function.

Oracle SQL Script to Check Index Fragmentation and Maintenance

1. Check Index Fragmentation and Determine Level 

This script checks the index fragmentation level for indexes on a specific table. It queries the all_indexes data dictionary view based on the schema name and table name, and displays the index name, table name, B-level (branching factor), number of leaf blocks, distinct keys, and clustering factor. Higher clustering factor values indicate potential fragmentation.

Oracle SQL Script for Index Usage and Performance:

1. Identify Underused or Unused Indexes 

 This script identifies underused or unused indexes in a specific schema. It queries the all_indexes data dictionary view based on the schema name, status, and index statistics (num_rows and leaf_blocks). The output displays the index name, table name, status, number of rows, and number of leaf blocks.

Oracle SQL Script to Retrieve Index Information - with Description and Sample Output

1. Query to list all indexes on a specific table or schema.

This script lists all indexes on a specific table. It queries the all_indexes data dictionary view based on the table name and displays the index name, table name, uniqueness (UNIQUE or NONUNIQUE), and status (VALID or INVALID) of each index.

Script to Analyzes the Efficiency of Indexes in an Oracle Database:

This script performs the following steps: 

 1. Creates a temporary table (index_analysis_results) to store the index analysis results. 

2. Loops through all non-system indexes (NORMAL index type) in the database (excluding system schemas and recycle bin objects). 

RMAN Script That Incorporates Various Backup and Recovery Operations

This script includes the following operations:

Full Backup:

• Allocates a channel for the backup destination.
• Performs a compressed backup of the database using the BACKUP AS COMPRESSED BACKUPSET DATABASE PLUS ARCHIVELOG command.
• Releases the allocated channel.