ANSI SQL PORTABILITY TO HADOOP HIVE conversion tool or macro - sql

I am working on hadoop hive solutions. My requirement is to convert ansi sql queries to hive queries by using a tool or excel macro. Is there any tool/macro exist? if yes, what are they; if not need suggestions to implement it. Is this possible? Do we have alternative sql queries in Hive for DMLs (like insert,update ... )? What are the pros and cons?
Any suggestions is highly appreciated....

I do not think that whole ANSI sql can be ported to hive because it does not support joins different from equ-join. So such SQL can not be ported.
Another point - there is no updates in hive - data is read only...
The rest looks very similar to ANSI SQL and I would suggest to try running queries as-is.

Related

How can I use PL Sql in Hive using Spark?

val hiveContext = new HiveContext(sc)
val s = hiveContext.sql("SELECT * FROM Test")
But don't know how to use PL SQL in hive. Please help me.
It does not make sense to use PL/SQL code in hivecontext.sql() as it requires a querystring and not procedure.
The method returns a new data frame and would not perform operations as usually done in an PL/SQL code.
https://spark.apache.org/docs/1.3.0/api/java/org/apache/spark/sql/hive/HiveContext.html
It appears the answer is "yes", which I found in about 20 seconds by googling "hive spark pl/sql". And it has a reference manual here
HPL/SQL is an open source tool (Apache License 2.0) that implements
procedural SQL language for Apache Hive, SparkSQL, Impala as well as
any other SQL-on-Hadoop implementation, any NoSQL and any RDBMS.
HPL/SQL is a hybrid and heterogeneous language that understands
syntaxes and semantics of almost any existing procedural SQL dialect,
and you can use with any database, for example, running existing
Oracle PL/SQL code on Apache Hive and Microsoft SQL Server, or running
Transact-SQL on Oracle, Cloudera Impala or Amazon Redshift.
HPL/SQL
language is compatible to a large extent with Oracle PL/SQL, ANSI/ISO
SQL/PSM (IBM DB2, MySQL, Teradata i.e), PostgreSQL PL/pgSQL (Netezza),
Transact-SQL (Microsoft SQL Server and Sybase) that allows you
leveraging existing SQL/DWH skills and familiar approach to implement
data warehouse solutions on Hadoop. It also facilitates migration of
existing business logic to Hadoop. HPL/SQL is an efficient way to
implement ETL processes in Hadoop
.

Hana Column Store dialect to Oracle 12c SQL

While trying to benchmark Oracle's Database Inmemory, we were looking for publicly available benchmarking data set and tools. The CH-benCHmark suited our requirement exactly, but it has HANA Column Store Dialect as part of the source files.
So, our requirement is to convert these HANA Column Store dialect SQLs to Oracle 12c SQLs. Google search returned the conversion from Oracle to Hana dialect not the reverse.
Has anyone came across this requirement? Is there a simple/direct way to do the conversion?
Any pointers will be much helpful.
Yes I have done this exercise! there's no direct way from HANA Dialect to Oracle Dialect, But you can make use of ORACLE_LOADER and it's semantics to effectively create Oracle Dialect! Only problem you may face would be the flow, where HANA's flow is totally different from Oracle's schema creation flow.
For example:
you can easily use LOAD FROM FILE... syntax in HANA, But you need an externally organized table in case of Oracle.

Convert sql server script syntax to oracle script syntax

I have an application that is supposed to support two types of databases SQL SERVER and ORACLE. So we've been working forever on SQL Server and now we are making this support.
My idea was to create a tool to generate the scripts of creating the database using CMO then convert those scripts to PL/SQL Oracle scripts and run them on Oracle.
My questions are:
Is this syntax conversion possible in code?
I need a guideline to make this kind of syntax conversion.
Do you have a better suggestion to maintain two types of databases (i mean when making a change of one of them, we dont have to make it to the other. we need a tool to make that change.)?
If you write using standard sql it should be mostly portable. Eg use fetch instead of top, SET #a=.. instead of Select #a=.. Use Merge for updates instead of join updates, CURRENT_TIMESTAMP instead of getdate() etc.

Move Data from Oracle to SQL Server

I would like to copy parts of an Oracle DB to a SQL Server DB. I need to move the data because the Oracle box is being decommissioned. I only need the data for reference purposes so don't need indexes or stored procedures or contstaints, etc. All I need is the data.
I have a link to the Oracle DB in SQL Server. I have tested the following query, which seemed to work just fine:
select
*
into
NewTableName
from
linkedserver.OracleTable
I was wondering if there are any potential issues with using this approach?
Using SSIS (sql integration services) may be a good alternative especially if your table names are the same on both servers. Use the import wizard via and it should create the destination tables for you and let you edit any mappings.
The only issue I see with that is you will need to execute that of course for each and every table you need. Glad you are decommissioning the oracle server :-). Otherwise if you are not concerned with indexes or any of the existing sprocs I don't see any issue in what you are doing.
The "select " approach could be very slow if tables are large. Consider writing pro*C in that case or use Fastreader http://www.wisdomforce.com/products-FastReader.html
A faster and easier approach might be to use the Data Transformation Services, depending on the number of objects you're trying to copy over.

Microsoft T-SQL to Oracle SQL translation

I've worked with T-SQL for years but I've just moved to an organisation that is going to require writing some Oracle stuff, probably just simple CRUD operations at least until I find my feet. I'm not going to be migrating databases from one to the other simply interacting with existing Oracle databases from an Application Development perspective. Is there are tool or utility available to easily translate T-SQL into Oracle SQL, a keyword mapper is the sort of thing I'm looking for.
P.S. I'm too lazy to RTFM, besides it's not going to be a big part of my role so I just want something to get me up to speed a little faster.
The language difference listed so far are trivial compared to the logical differences. Anyone can lookup NVL. What's hard to lookup is
DDL
In SQL server you manipulate your schema, anywhere, anytime, with little or no fuss.
In Oracle, we don't like DDL in stored procedures so you have jump through hoops. You need to use EXECUTE IMMEDIATE to perform a DDL function.
Temp Tables
IN SQL Server when the logic becomes a bit tough, the common thing is to shortcut the sql and have it resolved to a temp table and then the next step is done using that temp table.
MSSS makes it very easy to do this.
In Oracle we don't like that. By forcing an intermediate result you completely prevent the Optimizer from finding a shortcut for you. BUT If you must stop halfway and persist the intermediate results Oracle wants you to make the temp table in advance, not on the fly.
Locks
In MSSS you worry about locking, you have nolock hints to apply to DML, you have lock escalation to reduce the count of locks.
In Oracle we don't worry about these in that way.
Read Commited
Until recently MSSS didn't fully handle Read Committed isolation so you worried about dirty reads.
Oracle has been that way for decades.
etc
MSSS has no concept of Bitmap indexes, IOT, Table Clusters, Single Table hash clusters, non unique indexes enforcing unique constraints....
I get the impression most answers focus on migrating an entire database or just point to some differences between T-SQL and PL/SQL. I recently had the same problem. The Oracle database exists, but I need to convert a whole load of T-SQL scripts to PL/SQL.
I installed Oracle SQL Developer and ran the Translation Scratch Editor (Tools > Migration > Scratch Editor).
Then, just enter your T-SQL, choose the correct translation in the dropdown-list (it should default to 'T-SQL to PL/SQL'), and convert it.
I have to things to mention.
1) When I worked on Oracle 8, you could not do "Select #Result", you had to instead use the dummy table as follows "Select #Result from dual". Not sure if that ridiculousness still exists.
2) In the Oracle world they seem to love cursors and you better read up on them, they use them all the time AFAICS.
Good luck and enjoy,
it is not that different to MS SQL. Thankfully, I do not have to work with it anymore and I am back in the warm comfort of MS tools.
If you replace your ISNULL and NVL nonsense with COALESCE, it'll work in T-SQL and PL/SQL!
It's not trivial to map them back and forth, so I doubt there's a tool that does it automatically. But this link might help you out: http://vyaskn.tripod.com/oracle_sql_server_differences_equivalents.htm
The most important differences for plain T-SQL are:
NVL replaces ISNULL
SYSDATE replaces GETDATE()
CONVERT is not supported
Identity columns must be replaced with sequences <-- not technically T- or PL/ but just SQL
Note. I assume you do not use the deprecated SQL Server *= syntax for joins
#jodonell: The table you link to is a bit outdated, oracle has become somewhat more standards compliant after 9i supporting things like CASE and ANSI outer joins
I have done a few SQL server to oracle migrations. There is no way to migrate without rewriting the backend code. Too many differences between the 2 databases and more importantly differences between the 2 mind sets of the programmers. Many managers think that the 2 are interchangeable, I have had managers ask me to copy the stored procedures from SQL server and compile them in oracle, not a clue! Toad is by far the best tool on the market for supporting an oracle application. SQL developer is ok but was disappointing compared to toad. I hope that oracle will catch their product up to toad one day but it is not there yet. Have a good day :) chances are if you are migrating to oracle it is for a reason and in order to meet that requirement you will need to rewrite the back end code or you will have many issues.
In Oracle SQL Developer, there is a tool called Translation Scratch Editor. You can find it from Tools > Migration.
The Oracle SQL Developer is a free download from Oracle and it is an easy install.
If you're doing a one-off conversion, rather than trying to support two versions, you must look at Oracle Migration Workbench. This tool works with Oracle's SQLDeveloper (which you really should have if you are working with Oracle). This does a conversion of the schema, data, and some of the T-SQL to PL/SQL. Knowing both well, I found it did about an 80% job. Good enough to make it worth while to convert the bulk of procedures, and hand convert the remainder "tougher" unknown parts.
Not cheap ($995) but this tool works great: http://www.swissql.com/products/sql-translator/sql-converter.html
A few people have mentioned here converting back and forward. I do not know of a tool to convert from MSSQL to Oracle, but I used the free MS tool to convert a Oracle db to MSSQL and it worked for me and converted a large db with no problems I can call. It is similar to the Access to MSSQL tool that MS also provide for free. Enjoy
jOOQ has a publicly available, free translator, which can be accessed from the website here: https://www.jooq.org/translate
It supports DML, DDL, and a few procedural syntax elements. If you want to run the translation locally via command line, a license can be purchased and the command line works as follows:
$ java -cp jooq-3.11.9.jar org.jooq.ParserCLI -t ORACLE -s "SELECT substring('abcde', 2, 3)"
select substr('abcde', 2, 3) from dual;
See: https://www.jooq.org/doc/latest/manual/sql-building/sql-parser/sql-parser-cli
(Disclaimer, I work for the vendor)