What is Oracle SQL Loader and what is it used for?
SQL Loader is utility provided by Oracle which enables us to load data from flat files into database tables. It is well covered in the documentation (check the Utilities Guide). The key thing is that SQL Loader is an external OS program.
External tables were introduced in Oracle 9i, allowing us to define tables whose data is supplied from flat files. These provide most of the functionality of SQL Loader with a lot more convenience. For instance we can manipulate and re-format the data using SQL functions which is simpler than using SQL Loader's syntax. It also means that we can pull the data from inside the database rather than pushing it from the OS.
However, for loading huge volumes of data in ultra-quick time a well-tuned SQL Loader control file will beat external tables for performance. Also, if there is a complicated OS process associated with the data files - e.g. ftp, gunzip, pre-processing with sed or awk - it can be more convenient to call SQL Loader from inside the shell script rather than attempting to hook up with a database job. So SQL Loader is still useful in certain scenarios but it is not necessarily the automatic first choice.
It is one of Oracle's bulk data loading tools.
You use it to load data from flat files (such as CSV) into the database.
For details, please check their documentation (or this FAQ)
To transfer data from one Oracle database to another oracle database, we use oracle data pump. And in oracle versions previous to 10g we use oracle export/import. But if you want to transfer data from a non oracle database to an oracle database, you create a flat file of the data in the non oracle database and using SQL Loader load the data into oracle database.
Following is procedure to load the data from Third Party Database into Oracle using SQL Loader.
1.Convert the Data into Flat file using third party database command.
2.Create the Table Structure in Oracle Database using appropriate datatypes
3.Write a Control File, describing how to interpret the flat file and options to load the data.
4.Execute SQL Loader utility specifying the control file in the command line argument
Related
I'm trying to export an Oracle DB using Oracle SQL Developer having tables, sequences, view, packages, etc. with dependencies on each other.
When I use Tools -> Database Export and select all DDL options, unfortunately the exported SQL file does not preserve the other that is some DB objects should be created before some other.
Is there a way to make the DB export utility preserve object dependencies/order? Or Is there any other tool do you use for this task?
Thank you
Normally expdp does a pretty good job. Problems arise when there are dependencies on objects/users that are not part of the dump. This is because the counter part, impdp, does not add grants on objects that are not created by impdp. I call that the 'not created by me syndrome' that impdp has.
If you have no external dependencies (external meaning to schema's that are not part of the dump), expdp/impdp do a good job for you. You might not be able to use it if you can not have access to the database server since expdp writes it's files on the database server.
If you happen to have access to a database server that is able to connect to the original database, you could pull the data over into your local database using a database link.
I have a csv file which has to be bulk imported to oracle dB. I was working on other sybase dB engine before so I had a sample script which has the environment setup for it. Right now I have to do the process in a oracle dB so what should be the first line I know about the rest other parameters but want to know the path which has to be defined when I write
path/bcp dbtable in data.txt
If anyone could help what should be the path for oracle dB
The primary tools for bulk or flat file loading are:
SQL*Loader
External Tables (and here)
GUI Tools like SQL*Developer
It is much more cumbersome, but if necessary you can roll your own solution with the UTL_FILE PL/SQL package.
I have to pull some data from oracle and update the data in snowflake. And ofcourse the size of the data is 5gb.
Is there any procedure to connect to oracle database from snowflake? OR
Do I need to connect them using a programming language as python?
You'll need to unload the data from Oracle and load into Snowflake, as there are no "direct connect" options I've ever heard about.
I'd use SQL*Loader to unload, push the files to AWS S3 (or your cloud vendor's storage), and issue Snowflake COPY INTO TABLE commands, it should be fairly straightforward.
There is no equivalent to Oracle database links in Snowflake. You would need an external process to move the data from Oracle to S3. Then you can configure a Snowpipe task to load from S3 into Snowflake. See Loading Continuously Using Snowpipe for more information.
I would suggest to use python programming to extract and load data from oracle to snowflake. Since your oracle table is being updated daily write python program to generate merge statement dynamically to load your incremental data from oracle to snowflake.
Snowflake supports Java script based stored procedure so you can use stored procedure to generate merge statement dynamically by passing table name as parameter and you can call it via python.
Initial load from oracle to snowflake may take time as you have 5GB data from your source system.
I am Oracle Data base Bigginner. I am Confusing with this two words sql * plus and sql loader,Any one Tell me the difference between SQL loader and SQL * PLUS?
From the documentation:
SQLPlus is an interactive and batch query tool that is installed with every Oracle Database Server or Client installation. It has a command-line user interface, a Windows Graphical User Interface (GUI) and the iSQLPlus web-based user interface.
SQLPlus has its own commands and environment, and it provides access to the Oracle Database. It enables you to enter and execute SQL, PL/SQL, SQLPlus and operating system commands to perform the following:
Format, perform calculations on, store, and print from query results
Examine table and object definitions
Develop and run batch scripts
Perform database administration
You can use SQLPlus to generate reports interactively, to generate reports as batch processes, and to output the results to text file, to screen, or to HTML file for browsing on the Internet. You can generate reports dynamically using the HTML output facility of SQLPlus, or using the dynamic reporting capability of iSQLPlus to run a script from a web page.
SQLLoader loads data from external files into tables of an Oracle database. It has a powerful data parsing engine that puts little limitation on the format of the data in the datafile. You can use SQL*Loader to do the following:
Load data across a network if your data files are on a different system than the database.
Load data from multiple datafiles during the same load session.
Load data into multiple tables during the same load session.
Specify the character set of the data.
Selectively load data (you can load records based on the records' values).
Manipulate the data before loading it, using SQL functions.
Generate unique sequential key values in specified columns.
Use the operating system's file system to access the datafiles.
Load data from disk, tape, or named pipe.
Generate sophisticated error reports, which greatly aid troubleshooting.
Load arbitrarily complex object-relational data.
Use secondary datafiles for loading LOBs and collections.
Use either conventional or direct path loading. While conventional path loading is very flexible, direct path loading provides superior loading performance.
SQL* Plus is installed with every Oracle Database Server or Client installation. It has a command-line user interface, a Windows Graphical User Interface (GUI) and the iSQLPlus web-based user interface.
SQL Loader loads data from external files into tables of an Oracle database.It can also be Load data across a network.
SQL*plus is something that provides an access to the Oracle Database.
SQL Loader is you are loading the external data or files from your disk to Oracle database.
This throws me the below error:
the media family on device is incorrectly formed 3241.
I tried loading the .dmp file as .bak file and restored the db. It did not work.
Only way I know to extract from dmp is to use the "INDEXFILE" parameter for IMP, this will generate a readable SQL script with the DDL and DML.
However often times this script is not 100% usable as it (usually) wraps the statements, so some pre-processing may be required, for example parse the file by each discrete statement (INSERT, CREATE), join each statement into a single line then squirt into the target database. Having said that, you would probably need to pre-process anyway to translate Oracle to SQL server dialogue anyway.
Also, might not be so good for BLOB/binary type data.
The other indirect way to do this would be to create a bridge Oracle database, import the file into there, then use the normal extract and load tools to push the data into SQL server.
A *.dmp file in Oracle is nothing but a backup file. You meant to say restoring a Oracle DB backup file in SQL Server.
AFAIK, the answer is NO. You can't do that. Probably you can check, if there is any third party utility present using which you can perform a DB migration.
The dmp file comes in an Oracle specific format that cannot be parsed/interpreted by anything other than Oracle's imp tool. So, that means you cannot import the dmp file into SQL Server.
Of course there are ways to transfer data from Oracle to SQL Server but which one is optimal depends on your needs, amount of data, number of tables, number of Oracle schemas, datatypes etc etc.