(7 comments, 168 posts)
Marco Gralike, working for AMIS Services BV as a Principal Oracle Database Consultant in the Netherlands, has experience as a DBA since 1994 (Oracle 6). Marco is also eager and skillful in other fields, like Operating System Administration and Application Servers, mainly to find working, performing solutions. Marco has been specializing in Oracle XMLDB, since 2003, focusing on his old love, database administration and performance.
He is an Oracle XMLDB enthusiast ever since. He is also a dedicated contributor of the Oracle User Group community, helping people with their steep XMLDB learning curve. To this purpose, Marco also devoted his personal blog site to XMLDB and other Oracle issues. Marco is a member of the OakTable network and an Oracle ACE Director (specialization Oracle XMLDB).
Home page: http://blog.gralike.com
Posts by Marco Gralike
Yesterday I went to the Big Data machine engineered systems demo grounds, to get an insight, exclusive demo from Dmitry Lychagin. Dmitry, being part of the XDB team explained with a lot of enthusiasm the new XQuery connector for Hadoop. Although currently not yet released, but available shortly, he demonstrated the potential while using XQuery as a basis, a lot of transformation possibilities from Hadoop to another platform.
“Oracle XQuery for Hadoop” (OHX) has integration with Oracle Loader for Hadoop, Oracle noSQL DB and no (XSD) schema is needed to make this work. Can’t wait to get my hands on it and give a try with a simple VirtualBox setup with Hadoop and a database transforming van unstructured into relational or unstructured in XML or…
Thanks Dmitry for giving me all the (me Hadoop newbie) detailed info and demonstrating it.
Currently I am attending the “Schema less data management using SQL/JSON” session during Oracle OpenWorld. This session demonstrated the new upcoming feature (=not in the current release) in the 12c database which supports JSON data handling in the database. That is, of course, with the nowadays common disclaimer, it probably will, but is not guaranteed by Oracle that they actually also will do so as presented… Nether the less it would be, could be a welcome new functionality. Without going into the flame wars between the XML and JSON communities, JSON is widely used and probably therefor has its merits in current build solutions.
There will not be a new datatype, like the XMLType for XML content, but make current datatypes supportive for JSON data, following the current JSON standards, while creating a standard for these relational / JSON needs in a query method currently called SQL/JSON.Oracle’s More >
XMLIndex support for Hash Partitioning is now also supported in Oracle 12c. In Oracle 11 there was already support for RANGE and LIST partitioning, but not yet for HASH partitioning. Some examples for the later two: (more…)
There is a new default in town. Mark my words, you will encounter the following during your 12c life-cycle…
From the Oracle 12c Reference manual PGA_AGGREGATE_LIMIT:
PGA_AGGREGATE_LIMIT PGA_AGGREGATE_LIMIT specifies a limit on the aggregate PGA memory consumed by the instance.
There is no difference in behavior between PGA_AGGREGATE_LIMIT being explicitly set or being set to the default.
Actions Taken When PGA_AGGREGATE_LIMIT is Exceeded
Parallel queries will be treated as a unit. First, the sessions that are using the most untunable memory will have their calls aborted. Then, if the total PGA memory usage is still over the limit, the sessions that are using the most untunable memory will be terminated. SYS processes and background processes other than job queue processes will not be subjected to any of the actions described in this section. Instead, if they are using the most untunable memory, they will periodically write a brief summary of their PGA usage to a trace file.Parameter type Big integer Syntax
[K | M | G]Default value By default,
PGA_AGGREGATE_LIMITis set to the greater of 2 GB, 200% of
PGA_AGGREGATE_TARGET, and 3 MB times
New in Oracle 12c and one of the big new features in XMLDB is the XQuery Full Text functionality and, as mentioned in the post about XQuery Update, is the official W3C standard to handle unstructured pieces of XML content. The XQuery Full Text and XQuery Full Text Index extends the XQuery XMLDB language to efficiently and XML aware handle unstructured content in XML. So finally in Oracle 12c, we are able to handle “structured”, “semi-structured” and “unstructured” content, XML aware and based on standards, across the board with regards to XML content.XQuery Full Text FTSelection / Match
The following “Full Text FTSelection Operators” are supported:
- FTAnd (ftand)
- FTMildNot (not in)
- FTOr (ftor)
- FTOrder (ordered)
- FTUnaryNot (ftnot)
- FTWindow (window)
The following “XQuery Full Text Match Options” are supported:
- FTStemOption (stemming, no stemming)
The default behavior specified in the XQuery and XPath Full Text 1.0 Recommendation is used for each unsupported match option, with the following exceptions:
- FTLanguage (unsupported) – The language used is the language defined by the default lexer, which means the language that was used when the database was More >
New, new…? No, not really new, XQuery Update (W3C standard/draft 2011) was already implemented in 126.96.36.199.0, but is now officially also announced. Besides the XQuery Full Text support (XQFT for short, W3C standard/draft 2011), this is one of the big new features in Oracle 12c. With this update XQuery functionality, the XQuery standard is further expanded in a mature query language for XML (/unstructured) information.
Now also in Oracle 12c, this has immediate consequences for following, implementing a XQuery standard across the board. The following features, functions have now been given the status “deprecated” (most of them introduced in Oracle version 10.2) for updating XML data:
All Oracle SQL functions for updating XML data are deprecated. Oracle recommends that you use XQuery Update instead. These are the deprecated XML updating functions:
updateXML insertChildXML insertChildXMLbefore insertChildXMLafter insertXMLbefore insertXMLafter appendChildXML deleteXML
Although being signaled “deprecated”, be aware that they are still supported, but Oracle move to a position that the new XQuery Update functionality will be the basis for further More >