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how best to have a record versioning or tracking in relational database?

Re "the problem with sequence versioning (v1, v2, etc.) is that every lookup of "current" requires a nested subquery to find the maximum value. It's critical that you know how to find ...
Richard's user avatar
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What is the difference between using First..Last and 1..count in Oracle?

1 .. count is better because you can use it when a collection is empty. first .. last will raise an exception for an empty collection. Here is a good article on it. The precondition for using 1 .. ...
Matthew Moisen's user avatar
1 vote

Oracle database backup recovery

There are two separate task here: restore and recover database and perform upgrade. Let's start with the first one. Let's pretend you have instance of 10G installed. First of all you have to create an ...
SergeyA's user avatar
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1 vote

Is it any performance downgrade when query separate db (by db link) on same physical server

The simple answer is, "Yes, it will". If you compare performance between a query from the local tables and a query from remote tables - the local tables will always win. The db link will ...
White Owl's user avatar
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Oracle optimizer does not use column group information from multiple tables and misses correlation

Oracle, and most other DBMS I know of, will only gather statistics on the content of single tables. It can collect statistics at the table level (number of rows) and at the column level (number of ...
Andrea B.'s user avatar
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1 vote


The datafile has a high water mark. If you have dropped a 'segment' it doesn't automatically shrink the datafile. If you have a segment created or extended ABOVE the object you dropped, the space in ...
REW's user avatar
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1 vote

How to Make Queries on a DATETIME Column Efficient If My Primary Query Pattern is an Hour?

SQL Server and Oracle are different products. SET IDENTITY_INSERT table_name OFF is SQL Server syntax which has no equivalent on Oracle , the most similar might be generated by default as identity ...
Ergest Basha's user avatar
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0 votes

Freewares to migrate data from Oracle to Singlestore. And from Postgresql to Singlestore

Depends how large the database(s) is/are. Airbyte provides a free open source solution that might work. Fivetran might be another possibility. There are three methods to migrate from MySQL or ...
Pavan's user avatar
  • 101
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Best Practice for Oracle SGA and PGA Memory Components Size

Answering Your Question I wonder if there is any best practice for this configuration that could allow Oracle Database to utilize hardware even better? I don't think there are any recommendations ...
John K. N.'s user avatar
1 vote

Listing all declared advanced query rewrites in Oracle

select * from DBA_REWRITE_EQUIVALENCES Reference
Andy DB Analyst's user avatar
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What happens if sys.aud$ is full in Oracle?

SYS.AUD$ is used for auditing certain aspects of the Oracle Database instance. The information is normally stored in the SYSTEM tablespace. The SYSTEM tablespace again is based on files that are ...
John K. N.'s user avatar
0 votes

sqlplus column header misaligned

set tab off fixes the problem.
Brian Fitzgerald's user avatar
1 vote

Oracle temporary tablespace performance

Unless you have some evidence from AWR/ ASH that allocating extents is a particularly time-consuming part of your query runtime, this is probably the sort of micro-optimization that you'd consider if ...
Justin Cave's user avatar
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