Oracle

glennfawcett's picture

Importing geo-partitioned data… the easy way

 

setting the stage

I started at Cockroach labs back in June 2019 to help others learn how to architect and develop applications using a geo-distributed database.  There has been a resurgence in distributed database technology, but the focus on geo-distributed is quite unique to CockroachDB.  While the underlying technology is unique, developers and DBAs that come with a wealth of experience, need to know how to best use this innovative technology.  Given this situation, I thought it would be good to start a blog series to explore various topics facing anyone beginning to architect database solutions with CockroachDB.

To start using a database, the first step is to IMPORT table data so you can begin to see how the database performs and responds.  And thus the IMPORT series has started!

Franck Pachot's picture

kglLock()+1406<-kglget()+293<-qostobkglcrt1()+498<-qostobkglcrt()+248<-qostobkglcrt2()+412<-qospsis(…

kglLock()+1406<-kglget()+293<-qostobkglcrt1()+498<-qostobkglcrt()+248<-qostobkglcrt2()+412<-qospsis()+2511 <-qospPostProcessIStats()+2765<-qerltFetch()+1544<-qerstFetch()+449<-insdlexe()+364<-insExecStmtExecIniEngine()+1810<-insexe()+2283<-atbugi_update_global_indexes()+1656<-atbFMdrop()+3088<-atbdrv()+7719

Sorry for this title, but that’s exactly the subject: this short stack gives me enough information to understand the issue, reproduce it, open a SR, talk with friends, find a workaround,…

A Friday afternoon story

Here is how this started, on a database just migrated from 11g:

Jonathan Lewis's picture

Temp space

A question about hunting down the source of the error “ORA-01652 unable to extend temp segment by NNN in tablespace XXX” shows up on the Oracle-L mailing list or the Oracle developer community forum from time to time. In most cases the tablespace referenced is the temporary tablespace, which means the session reporting the error was probably trying to allocate some space for sorting, or doing a hash join, or instantiating a GTT (global temporary table) or a CTE (common table expression / “with” subquery). The difficulty in cases like this is that the session reporting the error might be the victim of some other session’s greed – so looking at what the session was doing won’t necessarily point you to the real problem.

Jonathan Lewis's picture

E-rows / A-rows

This note was prompted by an error I made at the UKOUG TechFest19 yesterday. It’s fairly well-known that when you read an execution plan that includes the rowsource execution stats – so you get the E-rows (estimated) and A-rows (Actual) reported – then a sensible check of the quality of the optimizer’s calculations is to compare the estimates and actuals allowing for the fact that the E-rows is “per start” and the A-rows is “cumulative”, so A-rows = E-rows * Starts.

The error I made yesterday was to forget that this relationship isn’t always true. In particular partitioning and parallel query introduced the need to be a little flexibility in reading the numbers – which I’ll demonstrate with a coupld of simple examples running under 12.2.0.1

oraclebase's picture

Video : SQLcl and Oracle REST Data Services (ORDS)

In today’s video we’ll demonstrate the ORDS functionality built into Oracle SQLcl.

This is based on this article.

There are loads of other ORDS articles here.

The star of today’s video is Arman Sharma, captured at Sangam 2015. Seems like yesterday.

Cheers

oraclebase's picture

Oracle Cloud : Free Tier and Article Updates

https://oracle-base.com/blog/wp-content/uploads/2019/11/free-220x300.png 220w" sizes="(max-width: 189px) 85vw, 189px" />

Oracle Cloud Free Tier was announced a couple of months ago at Oracle OpenWorld 2019. It was mentioned in one of my posts at the time (here). So what do you get for your zero dollars?

oraclebase's picture

Video : Oracle REST Data Services (ORDS) : OAuth Implicit

In today’s video we look at the OAuth Implicit flow for Oracle REST Data Services.

This goes together with a previous video about first-party authentication here.

Both videos are based on parts of this article.

There are loads of other ORDS articles here.

oraclebase's picture

Oracle Database 18c and 19c on Fedora 31

https://oracle-base.com/blog/wp-content/uploads/2019/11/fedora31-small-3... 300w" sizes="(max-width: 235px) 85vw, 235px" />

Fedora 31 was released a couple of weeks ago and I’ve done some Oracle installations on it.

Just a warning to explain why this is a bad idea for anything real.

With that out of the way, here are the articles.

kevinclosson's picture

Announcing Obfuscated Column Data Loading with SLOB

On November 18, 2019 I announced availability of SLOB 2.5.2. It is primarily a small bug fix release but also has an undocumented new feature. I want to say a few words about the feature in this post and will update SLOB with full support (e.g., documentation and slob.conf parameter support) in SLOB 2.5.3.  Some SLOB users might want this new undocumented feature as soon as possible–thus this blog post.

kevinclosson's picture

Announcing SLOB 2.5.2

SLOB 2.5.2 is available for download from Github. Please visit the SLOB Resources Page for the download URLs.

SLOB 2.5.2 is a bug fix release.

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