I' trying to implement server-side paging. Database cursor looks like a good approach for this. Does Impala supports database cursors like relational databases? The documentation does not explicitly mention that it does or does not.
Here is the official recommendation of doing paging in impala. Short answer : no cursor support. And there isn't a cursor feature in the near dev roadmap either.
Related
I want to know oracle 12 c Document Store RDBMS VS NoSql
I think that the Oracle 12c DocumentStore works similarly to MondoDB(schemaless-database).
But today I heard a shocking story.
Oracle12C database works similar to RDBMS. oracle12c document-store create a temporary schema and store data in database. So Oracle12c DocumentStore is not NoSql. Also, how to use Nosql as RDBMS service without separate installation? It just provides similar functionality, not Nosql.
and I said "That's one feature built into the ORACLE12C version, NoSql is correct."
No conclusion, I don't think I'm wrong, but I ask a question because I wanted to get an accurate answer. Please provide a answer or related documentation.
Progress/OpenEdge is not a SQL database and although it does have support for SQL (through the ODBC interface) that is not the natural way to access OpenEdge data. Progress applications are built using "ABL" (formerly known as "Progress 4gl") and some SQLish things like referential integrity constraints are implemented through procedural logic in 4gl code. Which makes things difficult if you are not really interested in learning ABL.
Has anybody successfully managed to use Apache Drill (https://drill.apache.org) to access Progress data? Are there any pointers particular to the combination of Progress and Apache Drill to share?
Short answer: No, this is impossible.
Longer answer: my admittedly cursory read of what Apache/Drill does lead to the mistaken conclusion that you can just access Progress (or anything else) via ODBC and then use Drill on top of it.
Apache/Drill is exposing itself via ODBC but currently the only datasources it can use are:
HBase
Hive
MapR-DB
Avro
Parquet
File system:
CSV (Comma-Separated-Values)
TSV (Tab-Separated-Values)
PSV (Pipe-Separated-Values)
Therefore at the time being Progress cannot be accessed by Apache/Drill.
I'm trying to move snapshots of data from our MongoDB into our Oracle BI data store.
From the BI team I've been asked to make the data available for ODI, but I haven't been able to find an example of that being done.
Is it possible and what do I need to implement it?
If there is a more generic way of getting MongoDB data into Oracle then I'm happy to propose that as well.
Versions
MongoDB: 2.0.1
ODI: 11.1.1.5
Oracle: 11.2g
Edit:
This is something that will be queried once a day, maybe twice but at this stage the BI report granularity is daily
In ODI, under the Topology tab and Physical Architecture sub-tab, you can see all technologies that are supported out of the box. MongoDB is not one of them. There are also no Knowledge Modules available for importing/exporting from/to MongoDB.
ODI supports implementing your own technologies and your own Knowledge Modules.
This manual will get you started with developing your won Knowledge module, and in one of the other manuals i'm sure you can find an explanation on how to implement your own technologies. (Ctrl-F for "Data integrator")
If you're lucky, you might find someone else who has already implemented it. Your best places to look would be The Oracle Technology Network Forum, or a forum related to MongoDB.
Instead of creating a direct link, you could also take an easier workaround. Export the data from the MongoDB to a format that ODI supports, and MongoDB can extract to. CSV or XML maybe? Then load the data trough ODI into the oracle database. I think... that will be the best option, unless you have to do this frequently...
Look at the blog post below for an option;
https://blogs.oracle.com/dataintegration/entry/odi_mongodb_and_a_java
Cheers
David
I finished my course on Oracle databases and have been playing with it since sometime. One of my friends told me that PostgreSQL is a very good database management system which has object oriented capabilities.
On an Oracle database, it is a straightforward and easy process to create materialized views. BUT despite of having heard that PostgreSQL supports materialized views from few people, I am unable to figure out how to do that.
Please advise.
For PostgreSQL version 9.2 and below, read the following article on how to create materialized views by using functions and triggers.
http://tech.jonathangardner.net/wiki/PostgreSQL/Materialized_Views
Since version 9.3, materialized views are natively supported:
For more information on this topic, please refer to the following articles on PostgreSQL documentation:
http://www.postgresql.org/docs/devel/static/sql-creatematerializedview.html
http://www.postgresql.org/docs/devel/static/rules-materializedviews.html
There's no native support for materialized views in postgres.
You could try to emulate them with triggers/stored procedures as described in this article.
Anybody know why the geoserver does not implement a direct sql query when setup a layer?
The developers just hadn't gotten around to it yet. (There is not a huge need for this feature since GeoServer can serve a database view as easily as a table.) However, now GeoServer is able to dynamically alter the SQL used to fetch feature data from databases. This functionality is discussed in the GeoServer users manual at http://docs.geoserver.org/stable/en/user/data/database/sqlview.html