MarkLogic TDE enables SQL 'like' access to the document data.
Hence via common ODBC driver, other BI tools could possibly access ML DB in a 'relation db' way. However the challenge I have is to know which SQL dialet ML supports.
For example, I want to find how to find the first 10 records to get a snippet of the data. I could do that with
select top 10 * from book (ms sql)
or
select * from book where rownum <= 10 (oracle sql)
How to do the same with MarkLogic SQL?
There are actually many such types of sql syntax questions. I need to find the equivalent of what I normally used with ms sql.
Is there a wiki page to show the difference between ML SQL and MS SQL?
In general, MarkLogic supports the syntax from the SQL92 standard.
Supported SQL Statements, Functions and Types
This section describes the SQL statements and functions supported in MarkLogic. The topics are:
Supported Statements
Supported Functions
Supported Types
Related
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
.
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.
I'm very excited by several of the more recently-added Postgres features, such as foreign data wrappers. I'm not aware of any other RDBMS having this feature, but before I try to make the case to my main client that they should begin preferring Postgres over their current cocktail of RDBMSs, and include in my case that no other database can do this, I'd like to verify that.
I've been unable to find evidence of any other database supporting SQL/MED, and things like this short note stating that Oracle does not support SQL/MED.
The main thing that gives me doubt is a statement on http://wiki.postgresql.org/wiki/SQL/MED:
SQL/MED is Management of External Data, a part of the SQL standard that deals with how a database management system can integrate data stored outside the database.
If FDWs are based on SQL/MED, and SQL/MED is an open standard, then it seems likely that other RDBMSs have implemented it too.
TL;DR:
Does any database besides Postgres support SQL/MED?
IBM DB2 claims compliance with SQL/MED (including full FDW API);
MySQL's FEDERATED storage engine can connect to another MySQL database, but NOT to other RDBMSs;
MariaDB's CONNECT engine allows access to various file formats (CSV, XML, Excel, etc), gives access to "any" ODBC data sources (Oracle, DB2, SQLServer, etc) and can access data on the storage engines MyIsam and InnoDB.
Farrago has some of it too;
PostgreSQL implements parts of it (notably it does not implement routine mappings, and has a simplified FDW API). It is usable as readeable since PG 9.1 and writeable since 9.3, and prior to that there was the DBI-Link.
PostgreSQL communities have a plenty of nice FDW like noSQL FDW (couchdb_fdw, mongo_fdw, redis_fdw), Multicorn (for using Python output instead of C for the wrapper per se), or the nuts PGStrom (which uses GPU for some operations!)
SQL Server has the concept of Linked Servers (http://technet.microsoft.com/en-us/library/ms188279.aspx), which allows you to connect to external data sources (Oracle, other SQL instances, Active Directory, File system data via the Indexing Service provider, etc.) and, if you really needed to, you can create your own Providers that can be used by a SQL Server Linked Server.
Another option within SQL Server is the CLR, in which you can write code to retrieve data from web services or other data sources as needed.
While this may not technically be "SQL/MED", it seems to accomplish the same thing.
Distributed query using local table joined to 4-part linked server query. I think case the remotetable filter might not be applied until after the entire table is pulled local (documentation is fuzzy on this and I've found article with conflicting opinions):
SELECT *
FROM LocalDB.dbo.table t
INNER JOIN LinkedServer1.RemoteDB.dbo.remotetable r on t.val = r.val
WHERE r.val < 1000
;
Using OpenQuery, remotetable filter is applied on the remote server, as long as the filter is passed into the OpenQuery 2nd parameter:
SELECT *
FROM LocalDB.dbo.table t
INNER JOIN OPENQUERY(LinkedServer1, 'SELECT * FROM RemoteDB.dbo.remotetable r WHERE r.val < 1000') r on t.val = r.val
Is there a SQL command that will list all the tables in a database and which is provider independent (works on MSSQLServer, Oracle, MySQL)?
The closest option is to query the INFORMATION_SCHEMA for tables.
SELECT *
FROM INFORMATION_SCHEMA.Tables
WHERE table_schema = 'mydatabase';
The INFORMATION_SCHEMA is part of standard SQL, but not all vendors support it. As far as I know, the only RDBMS vendors that support it are:
MySQL
PostgreSQL
Microsoft SQL Server 2000/2005/2008
Some brands of database, e.g. Oracle, IBM DB2, Firebird, Derby, etc. have similar "catalog" views that give you an interface where you can query metadata on the system. But the names of the views, the columns they contain, and their relationships don't match the ANSI SQL standard for INFORMATION_SCHEMA. In other words, similar information is available, but the query you would use to get that information is different.
(footnote: the catalog views in IBM DB2 UDB for System i are different from the catalog views in IBM DB2 UDB for Windows/*NIX -- so much for the Universal in UDB!)
Some other brands (e.g. SQLite) don't offer any queriable interface for metadata at all.
No. They all love doing it their own little way.
No, the SQL standard does not constrain where the table names are listed (if at all), so you'll have to perform different statements (typically SELECT statements on specially named tables) depending on the SQL engine you're dealing with.
If you are OK with using a non-SQL approach and you have an ODBC driver for the database and it implements the SQLTables entry-point, you possibly might get the information you want!
pjjH
details on the API at:
http://msdn.microsoft.com/en-us/library/ms711831.aspx
I have the displeasure of generating table creation scripts for Microsoft Access. I have not yet found any documentation describing what the syntax is for the various types. I have found the documentation for the Create Table statement in Access but there is little mention of the types that can be used. For example:
CREATE TABLE Foo (MyIdField *FIELDTYPE*)
Where FIELDTYPE is one of...? Through trial and error I've found a few like INTEGER, BYTE, TEXT, SINGLE but I would really like to find a page that documents all to make sure I'm using the right ones.
I've found the table in the link below pretty useful:
http://allenbrowne.com/ser-49.html
It lists what Access's Gui calls each data type, the DDL name, DAO name and ADO name (they are all different...).
Some of the best documentation from Microsoft on the topic of SQL Data Definition Language (SQL DDL) for ACE/Jet can be found here:
Intermediate Microsoft Jet SQL for Access 2000
Of particular interest are the synonyms, which are important for writing portable SQL code.
One thing to note is that the Jet 4.0 version of the SQL DDL syntax requires the interface to be in ANSI-92 Query Mode; the article refers to ADO because ADO always uses ANSI-92 Query Mode. The default option for the MS Access interface is ANSI-89 Query Mode, however from Access2003 onwards the UI can be put into ANSI-92 Query Mode. All versions of DAO use ANSI-89 Query Mode. I'm not sure whether SQL DDL syntax was extended for ACE for Access2007.
For more details about query modes, see
About ANSI SQL query mode (MDB)
This has it all. It's direct from MS, and actually tells you what the SQL datatype is that correlates to the GUI name.