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7
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2answers
1k views

If I SET ARRAYSIZE 1 in SQL*Plus, the records are still fetched in pairs. Why?

I thought about writing a simple tail -f like utility to "trace" the progress of some figures within the database: create or replace function tail_f return varchar2_tab pipelined as n number; ...
7
votes
1answer
107k views

“ORA-03113: end-of-file on communication channel” on startup

I have been reading posts here, on Oracle support, and anywhere else I can find for the last three days and I've given up on this problem... An Oracle database hung. Shutdown of the database sat for ...
7
votes
2answers
47k views

“ORA-01950: no privileges on tablespace 'SYSTEM' ” : What error is it?

Earlier I created a user : SQL>create user suhail identified by password SQL>User created. SQL>Grant create session,create table to suhail; SQL>Grant Succeeded. but when I login as ...
7
votes
4answers
816 views

Can this business logic be enforced by a conditional database constraint?

I am trying to duplicate the business logic embodied an intranet C# web application in the database so that other databases can access it and work under the same rules. This "rule" seems difficult to ...
7
votes
2answers
379 views

In Oracle, can we restore a database onto the same instance with a different name?

In SQL server I can restore a database onto the same instance with a different name. Eg: If there is a database DB_prod, I can take a full backup and restore it on the same instance with a different ...
7
votes
2answers
24k views

sqlnet.ora or tnsnames.ora changes require reboot?

Anytime you change Oracle's sqlnet.ora or tnsnames.ora files, does the system require a reboot? In my instance, I only have the Oracle client installed on the machine I'm referring to, but out of ...
7
votes
3answers
2k views

Oracle's left join and where clauses errors

CREATE TABLE "ATABLE1" ( "COLUMN1" VARCHAR2(20 BYTE), "COLUMN2" VARCHAR2(20 BYTE) ); CREATE TABLE "ATABLE2" ( "COLUMN1" VARCHAR2(20 BYTE), "COLUMN2" VARCHAR2(20 BYTE) ); ...
7
votes
2answers
4k views

Oracle 10g - How to prevent one user from hogging all resources?

I am wondering if there is any way to limit how much resources one user can take on my Oracle system. I want to limit some queries and systems from being able to hog all system resources when they run ...
7
votes
4answers
7k views

Multiple operations using WITH

Is there a way to execute multiple operations using the WITH statement? Something like WITH T AS ( SELECT * FROM Tbl ) BEGIN OPEN P_OUTCURSOR FOR SELECT * FROM T; SELECT COUNT(*) INTO ...
7
votes
1answer
301 views

What is “SAP on Oracle”

OK, total newb question. What is "SAP on Oracle", exactly. This link is talking about how SAP can run on Oracle (I think). I'm not understanding how this is working. My understanding: SAP is a ...
7
votes
2answers
6k views

How to extract Procedure, Function, etc. Source Code from an Oracle Export

I have generated an EXPDAT.DMP file of an Oracle database with the command: exp userid=usr/pass@db owner=own rows=n compress=n I then ran the following command to generate a file containing the '...
7
votes
4answers
32k views

How to find the actual space being consumed by indexes on a table in Oracle?

I want to find the actual space being consumed by indexes on a table in oracle 10g . I do not intend to include the space reserved by oracle for future usage. (The overhead by oracle should not be ...
7
votes
1answer
3k views

Why does an Oracle database require both the SYSTEM and the SYSAUX tablespaces?

Quoting from Oracle documentation about logical storage structures: A database must have the SYSTEM and SYSAUX tablespaces: Why is it compulsory to have these tablespaces?
7
votes
3answers
290 views

How do you protect against malicious PREPROCESSOR attacks in Oracle External Tables?

I'm a new DBA and I recently found out about the option of External Tables in Oracle using the PREPROCESSOR feature ( http://download.oracle.com/otndocs/products/database/enterprise_edition/utilities/...
7
votes
2answers
9k views

Oracle 11g: performance improvements of inserts

I have a table of 500 millions of rows (and growing) I did the following to improve performance of inserts: On database side: dropped all indexes and constraints disabled logging On application ...
7
votes
2answers
26k views

How and when to use sys_refcursor in oracle

Can some one give me a small explanation about how and when should someone use sys_refcursor ?
7
votes
1answer
164 views

Cardinality is so far off from reality

I've got a table where the cardinality for plans just seems waaaaaay too high - despite updating stats and even trying dynamic sampling for Oracle 11gR2. select count(*) from table1 where col1 = ...
7
votes
3answers
1k views

What methods are available to create a snapshot of an oracle database for testing purposes?

I am new to databases and have just been assigned to work with Oracle. We want to create a snapshot of the database for testing purposes that will allow us to revert back once we're done. I'm a bit ...
7
votes
1answer
1k views

Can I use Oracle Standard or Enterprise edition for my own training purposes?

Question is about Oracle licensing terms. I would like to learn more about Oracle Database administration. Unfortunatelly I am using 32 bit verison of LInux, so I can't install Oracle 11 XE (I can't ...
7
votes
2answers
5k views

Oracle's Merge v. Select->Update/Insert

What is the faster statement? A MERGE or Select->Update/Insert depending on if it returns a value? I'm trying to optimize a database, but I haven't found any speed tests comparing the two. I found ...
7
votes
2answers
60 views

Oracle 10g: Is it possible to designate a undo point?

I was wondering if it is possible to designate a point in time, then later "roll-it-back" to that state (undo DDL and DML changes). Maybe using a record of changes and then executing the reverse? Does ...
7
votes
2answers
276 views

Why is Oracle using the index here?

Name Null Type -------- -------- --------- ID NOT NULL NUMBER(4) GROUP_ID NUMBER(4) TEXT CLOB There is a btree index on group_id. Here's how many ...
7
votes
2answers
404 views

Exporting database Oracle 7.3 on Windows NT 3.51

How to take dump files on Oracle7.3 running on Windows NT 3.51? Should you stand in the Orant/bin folder and run one of the programs there like> exp73 SYSTEM/password@[dbinstance] FULL=Y LOG=EXPORT....
7
votes
1answer
25k views

PLS-00306 Error: How to find the wrong argument?

PLS-00306: wrong number or types of arguments in call to 'string' Cause: This error occurs when the named subprogram call cannot be matched to any declaration for that subprogram name. The ...
7
votes
3answers
168 views

Tablespace on ephemeral storage

For performance reasons in some scenarios, e.g. Amazon EC2, you have access to a faster and cheaper storage device, which loses all its data on reboots, so it is called "ephemeral". This question is ...
7
votes
1answer
935 views

Map Oracle roles to Active Directory groups?

Is there any built-in way to map Oracle database roles to Microsoft Active Directory groups?
7
votes
2answers
8k views

Can I use OpenLDAP to authenticate users in Oracle?

I like to use OpenLDAP to authenticate my Oracle users. It should be possible to fetch at least the password from the directory. There appearently is something for the Oracle LDAP servers, but would ...
7
votes
2answers
27k views

How to free up disk space? which logs/directories to clean?

I want to free up the disk space on my Linux machine. I've drill down the space usage and found that the following directories have a big size /u01/app/11.2.0/grid/cv/log /u01/app/11.2.0/grid/log/...
7
votes
2answers
2k views

Oracle 12c Express Enterprise Manager webpage does not load

Problem summary When browsing to the Oracle 12c EM Express webinterface, the page times-out when using a URL like: http(s)://hostname:5500/em http(s)://hostname.domain:5500/em When using a url ...
7
votes
1answer
2k views

Generate XML using Oracle XML schema

I have some XML schema definitions that have been registered using DBMS_XMLSCHEMA. I have created tables using the XMLTypes generated. I can create XML using XMLQuery and if I understand correctly, ...
7
votes
1answer
90 views

Parallel option performing worse on cluster

I'm trying out oracles parallel option on a cluster and surprisingly I am getting worse results with the parallel option. I was expecting some improvement with the parallel option but certainly not ...
7
votes
1answer
1k views

Find active values of SQLNET.ORA parameters on server

How can I find the active values of SQLNET.ORA parameters on the server? I know how to find the SQLNET.ORA file but there's no guarantee the values in that file are actively used. Parameter changes ...
7
votes
5answers
18k views

Oracle returns an error ORA-01031: insufficient privileges

Oracle returns an error "ORA-01031: insufficient privileges" When I run sqlplus / as sysdba but sqlplus sys/oracle123 as sysdba doesn't, why? Oracle version: Oracle Database 10g Enterprise Edition ...
6
votes
2answers
4k views

A database in MySQL is a schema in Oracle : I do not understand this statement

Please help me understand this statement: A database in MySQL is a schema in Oracle. I have just started to use Oracle and I find it different from other RDBMS softwares I have used like MSSQL, ...
6
votes
4answers
1k views

Does an IOT guarantee order in a select?

We need to add a priority column to a table that gets hit about 250 times a second, approx 170 selects, 125 inserts and 60 updates. The column will be a simple number(1). The priority does not matter ...
6
votes
3answers
1k views

For Oracle, we mount the instance to the database or mount the database to the instance?

The following text is extract from oracle documentation. Start the instance, and mount and open the database. This can be done in unrestricted mode, allowing access to all users, or in ...
6
votes
2answers
6k views

Is Oracle DB licensing needed for a test environment?

I'm planning to setup an Oracle Standard Edition instance on a server in our test environment. Do I need to purchase a license for this?
6
votes
2answers
211 views

How the indexes are managed?

I am trying to understand how the indexes are managed for below common data types: 1- Numeric (Integer, Decimals) 2- String (Varchar, Char) 3- DateTime I have few questions: 1- How the indexes are ...
6
votes
3answers
72k views

Oracle SQL - CASE in a WHERE clause

Is it possible to somehow do this? WITH T1 AS ( SELECT 1 AS SEQ, 'NOTHING 1' AS SOME_TYPE FROM DUAL UNION ALL SELECT 2 AS SEQ, 'NOTHING 2' AS SOME_TYPE FROM DUAL UNION ALL SELECT 3 AS SEQ, '...
6
votes
4answers
2k views

How to document Oracle database?

I'm new to Oracle databases. I have used to SQL Server and the description fields (MS_Description) for tables and columns for documentation purposes. Is there an equivalent for Oracle? What is the ...
6
votes
2answers
36k views

How to get a list of locked accounts / check that account is locked?

I can use following statement to unlock an account: ALTER USER username ACCOUNT UNLOCK But which statement can I use to verify that account is currently locked out?
6
votes
1answer
6k views

How can I query names using regular expressions?

How could I search for a specific pattern in a column? For example, I like to get all user names that start with either letter A or B. (btw: this is tagged oracle, but it might be interesting in ...
6
votes
2answers
28k views

How to set an Oracle user's default schema?

I created a few new users in Oracle. However, when running sqlplus, they all need to fully qualified the table names in query. What's the best way to set a default schema for these new users?
6
votes
3answers
1k views

Is there a need to keep refreshing the indexes from time-to-time?

This question is common for all the database products I use, viz. SQL Server, MySQL, Oracle and PostgreSQL. I have created a fresh database and the tables, at present, have no records. I have created ...
6
votes
3answers
725 views

What are the top 5 design decisions which need to be made when implementing a database?

I am implementing an Oracle System to store event alerts from an application so I guess all the schema, database design will be handled by the application through a sript. I am new to Database design,...
6
votes
4answers
17k views

Building Dynamic Oracle Where Clause

I'm working on application that uses dynamic query to do a select statement based on user input, after discussing security with DBAs they want me to convert my dynamic select statement into Stored ...
6
votes
2answers
105 views

Will the Oracle optimizer still plan a join if I'm not reading any columns in the joined table?

Suppose I have the following view: CREATE VIEW dummy AS SELECT a.some_column, b.other_column FROM a LEFT JOIN b USING (key_column); When I do a SELECT some_column FROM dummy, is there a way to ...
6
votes
2answers
5k views

How do I query to pull all data in row based MIN and MAX service date?

I'm very new to Oracle SQL especially in the Pentaho report builder. It lets you do some things and block others. PL/SQL is not available so I must do this in a query. I need to be able to pull ...
6
votes
2answers
38k views

How do you get the explain plan?

Can some one please explain a bit about explain plan, and how does one get the explain plan for a query. Also, if there is any sql script which can be used as utility for this, that would be great.
6
votes
3answers
2k views

Clustered index in SQL Server vs index organized tables in Oracle

I am making the transition as a database developer from SQL Server to Oracle and found some fantastic resources here already (How to make a transition from SQL Server DBA to Oracle? and As a DBA, how ...