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4
votes
1answer
29k views

temporary table inside procedure oracle

I'm in a situation right now. I'm migrating several procedures from Mysql 5.0 to Oracle 11g. Mysql procedures allow me to: 1. Create temporary tables 2. Insert data into temporary tables / Query these ...
13
votes
2answers
85k views

How is the default tablespace determined when creating a table?

The Tablespace parameter is optional when creating tables. Upon execution of a CREATE TABLE statement, Oracle assigns the default one if it was not defined. In the default database there is a ...
9
votes
3answers
3k views

How can I ensure that only one copy of a procedure is running in Oracle?

We have the need to ensure that only one copy of a particular procedure is running in Oracle. If it is already running and a user tries to open another, then it should error. Whats the best method ...
8
votes
1answer
19k views

How can I import the contents of an Oracle database into Visio to create an Entity Relationship Diagram?

I have an Oracle database, and I would like to create an ERD in Visio 2007 Pro. I have so far looked at DBMS_METADATA.GET_DDL commands to generate DDL. I know that I can import an Access DB into ...
8
votes
2answers
12k views

Why do we need to backup Oracle archive logs along with datafiles

Oracle® Database Backup and Recovery Basics 10g Release 2 (10.2) says that Archived redo logs are the key to successful media recovery. Back them up regularly. But, I wonder, why backups of ...
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 ...
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
5answers
20k views

Simplified/automated datafile free disk space reclaim

On Oracle version 11g: After Googling, I can't find a simple way to reclaim free space after deleting a table. I've found a lot of explanations, telling how the datafile becomes fragmented, the big ...
5
votes
3answers
1k views

How to store many smallish time-series in a relational DB?

Input Data Multiple Tests Beds generate measurement data of various complexity. In it's most basic form, not considering any meta-data, one measurement on a Test Bed will be a small (1 - a few ...
4
votes
7answers
44k views

How to export an ER diagram from an Oracle DB?

I am developing this application with an Oracle database. I haven't been documenting the data model, but now an auditor wants to have an entity relationship diagram of my database. There are many ...
3
votes
1answer
6k views

Oracle: Full database (user) restore requires drop?

In our development environment (Oracle 11g), we often have to restore databases (users) to previous versions to test upgrades, verify defects, etc. We are using expdp/impdp to perform our ...
2
votes
1answer
1k views

Oracle 10gR2 to 11gR2 upgrade - performance hit [closed]

We've recently upgraded from Oracle 10gR2 (10.2.0.4 ) to 11gR2 (11.2.0.3) and we are noticing a significant hit in performance although execution plans are the same for the offended queries before and ...
1
vote
3answers
10k views

Remove ORA-01100:DATABASE ALREADY MOUNTED

I am using Oracle 11g and there is a database create during installation name "xyz" and user "xyz".Now i created a user 'abc' and gave following permission to abc. "CREATE SESSION, ALTER SESSION, ...
0
votes
3answers
594 views

Can a RDBMS connect to a remote server, execute a select query and copy them into a local table just with SQL commands?

I'm sorry it may sound stupid but I've been wondering about how multiple databases are automated before the virtualization era. Can a DB Adminsitrator make a stored procedure to get data from a remote ...
11
votes
1answer
54k views

How do I declare and use variables in Oracle?

My main skills are with SQL Server, but I have been asked to do some tuning of an Oracle query. I have written the following SQL: declare @startDate int select @startDate = 20110501 And I get this ...
9
votes
2answers
2k views

Oracle Shutdown Method

Shutting down a database before doing an upgrade or a patch can be done several ways. shutdown immediate; or shutdown abort; startup restrict; shutdown immediate; or shutdown abort; startup ...
9
votes
1answer
1k views

Do Oracle databases use Java internally?

My question is fairly simple. Is Java used internally by Oracle in their DBMSs?
9
votes
2answers
4k views

Why can't I read Oracles CLOB columns via SQL-SERVER 2008 linked server?

I want to access data in an Oracle 11g database from SQL-Server 2008 I set up a linked server and when I execute select * from [Link_server_name]..Oracle_schema.Oracle_table and Oracle_table ...
7
votes
2answers
3k 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
6k 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
2answers
905 views

Resources for SQL Server developer migrating to Oracle

What resources can you recommend for a SQL Server developer wanting to learn Oracle basics? I am looking for a comprehensive whitepaper or blog post describing differences between these systems and ...
6
votes
2answers
191 views

Precision of NVARCHAR2 column is 1.5 times lower than displayed by desc command

I wanted to update precision of an nvarchar2 column and came across an interesting case. I have tried to replicate it below: create table test_table1 (col1 nvarchar2(100)); table TEST_TABLE1 ...
6
votes
1answer
86 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 ...
6
votes
2answers
103 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
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?
5
votes
3answers
3k views

Do roles have an owner in oracle?

Suppose that I have logged in to oracle database using user X, then user X creates some roles using create role command. I want to know that is user X the owner of the roles? Can I select all roles ...
5
votes
2answers
8k views

Database logon trigger

To block a particular user and IP combination on an Oracle Database , I created the following trigger, and compiled without errors. Create or replace trigger you_may_not_login after logon on database ...
5
votes
4answers
11k views

Why does = NULL not work in Oracle?

I recently realized that we need to use a special syntax IS NULL to compare a literal to NULL. Why does = NULL not work here?
5
votes
3answers
4k views

How to handle multiple Oracle homes?

On my desktop I have an Oracle client and and Oracle ODAC installed in different homes. I need ODAC because there ADO components off the Client installation don't work correct with CLOB data. I think ...
4
votes
2answers
12k views

Estimate a Database Size

I have to do some project, and need to estimate the DB size. I'm gonna to use Oracle in the project, because will have a lot of transactions and size. But in the "presentation" I need to specify, in 5 ...
4
votes
3answers
26k views

Oracle 11g - Create Database fails?

I've just installed Oracle 11g and linked it to SQL Developer. I want to create a database for my django install. CREATE database 'django'; Error starting at line 1 in command: create database ...
4
votes
3answers
753 views

Is Oracle DB immune to the InnoDB deadlocks found in MySQL?

It seems odd to me that MySQL would not handle this internally: "Deadlock found when trying to get lock; try restarting transaction" Does Oracle DB work around this issue? After all, Oracle owns ...
3
votes
1answer
9k views

Oracle program “lsnrctl” is missing after the installation of 32bit Oracle client

I cleaned up my computer for all old Oracle stuff using Uninstall (OUI) and then later used regedit to delete all references to Oracle and then deleted all remains of Oracle directories. I have HP ...
3
votes
2answers
8k views

Troubleshooting Oracle ORA-08103 - object no longer exists

I am getting this error from Oracle intermittently. A trigger is truncating a partition from a partitioned table while a long-running query is running against it. Since I'm truncating a different ...
3
votes
2answers
13k views

Improve BLOB Writing Performance in Oracle 11g

I have an application that writes a lot of rows into a table that contains a blob column. The average size of the blob is 3k bytes. Is there any buffer that i can resize to improve inserts into this ...
2
votes
1answer
14k views

What is the best way to insert a XML input to an oracle table in stored procedure?

I want to write a stored procedure which has a XML input (clob type) and inserts the data to a table. my XML structure is something like this: <rowset> <row> ...
2
votes
2answers
4k views

Querying a database efficiently for a huge chunk of data

Here is my query SELECT * FROM ( SELECT a.*, rownum rnum FROM ( SELECT id, data FROM t ORDER BY id ) a ...
2
votes
1answer
703 views

Preloading a Java library in DB2, similar to ORACLE's loadjava

Edit to add details to clarify, based on Chris' comment: A Java stored procedure depends on external libraries. Locally it compiles successfully, since they are added to the classpath. But when ...
2
votes
1answer
206 views

SQL from/where or join?

I was wondering performance wise what would be faster a join or a from and where query. I am trying merge and update query but performance is terrible?
1
vote
1answer
164 views

Startup oracle database 12c manually with SQL*Plus command not when OS loads

I changed oracle instance to manually start from services.msc (service name is "OracleServiceORCL"), Because I want to start it up manually with SQL*Plus commands whenever I want, not with OS load. ...
1
vote
2answers
516 views

Oracle nologging impact for REDO Generation

Oracle database is on noarchivelog mode and tablespace is configured with nologging option keeping there will not be a situation to recover any data in mind. Following scenario was occured during ETL ...
1
vote
1answer
3k views

ORA-00942: table or view does not exist while creating synonym

We are using oracle 11g, the db structure goes like this: We have users CST and FAS. CST contains a table ST_CAT2, a public synonym ST_CAT has been created for the table CST.ST_CAT2 as a SYS user. ...
0
votes
3answers
159 views

Allowing users to compile / run PLSQL and SQL

As a DBA - assuming my users are knowledgeable with PLSQL and SQL - why would I not grant my users privileges to compile and run their own PLSQL code. We have an MI database environment where the data ...
9
votes
1answer
3k views

Why am I NOT getting a mutating table error in trigger?

It's (or at least was) known that you cannot use DML statements on a mutating table inside a trigger. An excerpt from the Oracle documentation: A mutating table is a table that is being modified ...
9
votes
2answers
5k views

Updating 700 million rows to same value

I've got a data warehouse (oracle) where I need to set a column to the same value for all 700 million rows. I don't have admin access, or access to an admin, so this needs to be accomplished with ...
8
votes
1answer
1k views

Materialized views in oracle

How are materialized views implemented in oracle? I've created a materialized view in oracle. What I now see is a quite normal table with a job. Are materialized views translated into tables & ...
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
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 ...
6
votes
1answer
3k views

MySQL or Oracle Associate Certification?

I have 15+ years in software development and 7+ in web development, and I want to get a certification in another area, like DBA. I have 7+ years of experience like MySQL developer. Which is better for ...
6
votes
2answers
753 views

Oracle Advanced Queuing LIFO

With Oracle's Advanced Queuing is there a way to dequeue messages in a LIFO (last in first out) order? There is an indication through a lack of information that this is not an option, but perhaps ...