Oracle is a RDBMS (Relational Database Management System) created by Oracle Corporation. It supports a large number of languages and application development frameworks. Its primary languages are SQL, PL/SQL and Java. Also included is support for C (Pro*C, OCI and EXTPROC), C++ (OCCI) and Java (JDBC) ...

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Getting “ORA-00942: table or view does not exist” while table does exist

I'm fairly new to Oracle database. I have installed Oracle Database 11g R2 on Oracle Linux 6. I have successfully created a new database with dbca and connected to the database using: $ sqlplus "/ as ...
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4answers
3k 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
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2answers
4k 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
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1answer
16k views

What happens when you modify (reduce) a column's length?

Lets say I have two columns of type NUMBER (without precision, and scale) and VARCHAR(300). I saw that these columns are way too large for my data, so I want to modify them to NUMBER(11) and ...
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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
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3answers
255 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 ( ...
7
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3answers
5k views

Multiple Oracle Instances — is this a good practice?

One of my clients has deployed our product's db into a Solaris machine which already has 3 instances of Oracle. So, right now there are 4 instances of Oracle running on the same machine. And now we're ...
7
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2answers
6k 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
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1answer
158 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
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2answers
397 views

Is this a new common pattern in Oracle Where exists ( Select NULL FROM…)?

Years ago, it was common to write where exists (Select * from some_table where some_condition) Last year I noticed that many t-sql scripts switched to using the number 1 instead of the star where ...
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3answers
1k views

Is it bad idea to create foreign keys on the tables in a different schemas in the same database for big applications?

I am working on the transfer a big pl/sql web-based application to the dedicated server. This application is located in one schema with 70 packages of programm code. This application was made ...
7
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2answers
59 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
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2answers
264 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
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1answer
17k views

How can I Estimate Table Sizes within Schema (Oracle)

I'm trying to estimate the table sizes within my schema (in MB). This is what I have so far: SELECT table_name, owner, last_analyzed FROM all_tables I'm fairly new to SQL so I have no idea how I ...
7
votes
2answers
2k views

Limit redo for materialized view complete refresh or manual equivalent

A materialized view(MV) log can be used to allow a MV to do a fast refresh which only modifies the data that has changed. However, various conditions prevent the MV from using the log and therefore ...
7
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1answer
3k views

Oracle materialized view refresh schedule

Since I see that it is possible to specify an expression like sysdate + 1, here are my questions: Is it possible to specify the exact time of the refresh for materialized views in oracle? Is it ...
7
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1answer
5k 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
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3answers
117 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
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1answer
641 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
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1answer
465 views

How can I rewrite for SQL Server a trigger that writing for Oracle?

How can I rewrite for SQL Server a trigger that was originally written for Oracle ? Here is my Oracle trigger code: CREATE OR REPLACE TRIGGER P000KUL_TEST BEFORE INSERT ON P000KUL REFERENCING NEW AS ...
7
votes
1answer
402 views

Temporal Validity and Primary/Foreign Key Relationships

I've read through several of the oracle tutorials that show temporal validity and time features. However, in the examples I'v read, there is no primary key used in the demo tables. ...
7
votes
4answers
21k views

Execute a script with SQLPlus containing blanks, semi-colons, and forward slashes

Occasionally I will get a script that will run fine in SQL Developer or Toad, but requires modification in order to be run successfully from SQL*Plus. Here is a worst case example containing multiple ...
7
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1answer
1k 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
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1answer
415 views

Designing Simple Schema for Disaggregation of Demand Forecast

I am doing a simple database design task as a training exercise where I have to come up with a basic schema design for the following case: I have a parent-child hierarchy of products (example, Raw ...
7
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4answers
14k 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 ...
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5answers
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In Oracle how do I save a sequence.nextval in a variable to be reused in multiple inserts?

I'm writing a script to populate some tables with data for testing. I would like to write something like the following but I don't know how to do it (I'm Oracle 11g) SET ENABLED_USER_ID = ...
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3answers
13k views

Pivot rows into multiple columns

I have a SQL Server instance that has a linked server to an Oracle server. There is a table on the Oracle server called PersonOptions which contains the following data: ╔══════════╦══════════╗ ║ ...
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votes
4answers
791 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
2answers
4k 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
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3answers
11k views

Why use explicit cursors instead of regular loops?

I've been writing basic web apps for a year (for an Oracle db), and since the functions are pretty simple, most of us stick with regular FOR loops to get our data: for i in (select * from STUDENTS) ...
6
votes
2answers
2k views

Is DB2 more reliable and stable compared to PostgreSQL or MySQL?

Always i was using MySQL or PostgreSQL for my projects such as Web/Desktop apps. I had data loss few times and thanks to old backup i was always up and running. But for a recent project for Airport, ...
6
votes
4answers
1k 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 ...
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2answers
7k views

SQL Server Express vs. Oracle Express Edition vs DB2 Express-C

I have been trying to compare the features of the SQL Server Express, Oracle XE and DB2 Express-C, but find it difficult to compile all the differences into one place. Especially the current ...
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3answers
519 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
24k views

How to get rid of ORA-28002 message the password will expire within 6 days?

I have a user getting an ORA-28002 indicating that the password will expire within six days. I ran the following: ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED; But when I try to log ...
6
votes
1answer
6k views

When a record is locked in Oracle, can we know which record is locked?

When a record is locked ,can we know which one is locked? How can I get the record rowid or something else info? I can get some info by this sql SELECT ...
6
votes
2answers
3k 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
4answers
646 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 ...
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 ...
6
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2answers
917 views

Does it make sense to consolidate Oracle databases?

I am more experienced with SQL Server and Sybase than Oracle, and understand those products well. I've been asked to look for ways to reduce the server estate running Oracle. I understand that an ...
6
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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 ...
6
votes
1answer
279 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 ...
6
votes
2answers
343 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 ...
6
votes
2answers
872 views

SQL ANSI JOIN precedence

I have a query that looks like this: SELECT * FROM TBLA A LEFT JOIN TBLB B ON A.Col1 = B.Col2 RIGHT JOIN TBLC C ON B.Col3 = C.Col4 JOIN TBLD D ON C.Col5 = D.Col6 In which order ...
6
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1answer
31k 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 ...
6
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1answer
2k 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?
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1answer
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What's the difference between a v$ view and its dba_ equivalent?

What's the general difference between a v$ view and its dba_ equivalent? Take, for example, v$tablespace and dba_tablespaces.
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2answers
530 views

Can Oracle be installed on Windows without being an administrator?

Can the oracle software be installed on windows without having administrator privileges?
6
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3answers
785 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 ...
6
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2answers
40k views

How do you show SQL executing on an Oracle database?

How can you show the SQL that is currently executing on an oracle db? Extra information that would be useful would include user, session id etc.