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How to Save 7 Keystrokes with dbms_xplan

An almost unknown simplification in the usage of dbms_xplan is possible since Oracle 12.2. Sometimes, there are small details that makes our job (a little bit) easier. In one of his presentations at the Kscope19 conference, Kim Berg Hansen mentioned an...

Veröffentlicht 16 Jul 2019 22:22 von triBLOG

Gespeichert unter: Oracle, Performance, PL/SQL, Oracle 12c

Bitmap-based COUNT(DISTINCT) Functions in Oracle 19c

Oracle 19c provides a set of new SQL functions for bitmap operations. They allow fast computation of COUNT(DISTINCT) expressions. What is the purpose of these functions? The Oracle documentation is very sparse, but at least it tells us that the main …...

Veröffentlicht 20 Apr 2019 21:13 von triBLOG

Gespeichert unter: SQL, Oracle, Performance, Materialized Views, oracle 19c

Materialized View Refresh for Dummies

Materialized Views are often used in data warehouses to improve query performance on aggregated data. But what if it takes too long to refresh the materialized views? Here are some basic rules to improve refresh performance. Unlike indexes, materialized...

Veröffentlicht 18 Feb 2019 21:19 von triBLOG

Gespeichert unter: SQL, Oracle, Performance, ETL, Materialized Views

Data Types of Join Columns

The data type of primary key and foreign key columns has an impact on the query performance. This should be considered in the design decision of keys in a Data Vault schema. In a performance review of a customer project, … Continue reading →...

Veröffentlicht 11 Dez 2018 18:16 von triBLOG

Gespeichert unter: Oracle, Performance, Data Vault Modeling, ADWC

Star Schema Optimization in Autonomous Data Warehouse Cloud

Oracle Autonomous Data Warehouse Cloud does not allow to create indexes. Is this a problem for star schemas because no Star Transformation can be used? Or are the required bitmap indexes automatically created? A look under the hood of ADWC. … Continue...

Veröffentlicht 13 Sep 2018 18:03 von triBLOG

Gespeichert unter: Oracle, Cloud, Performance, in-memory, Dimensional Modeling, ADWC

10 Tips to Improve ETL Performance – Revised for ADWC

The Autonomous Data Warehouse Cloud (ADWC) is a self-configuring, fast, secure and scalable platform for data warehouses. Does this mean we don’t have to take care anymore about performance of our ETL processes? Which performance tips are still important...

Veröffentlicht 20 Jul 2018 15:29 von triBLOG

Gespeichert unter: SQL, Oracle, Cloud, Performance, ETL, ADWC

Gathering Statistics in the Autonomous Data Warehouse Cloud

Optimizer statistics are essential for good execution plans and fast performance of the SQL queries. Of course, this is also the case in the Autonomous Data Warehouse Cloud. But the handling of gathering statistics is slightly different from what we …...

Veröffentlicht 11 Jul 2018 17:46 von triBLOG

Gespeichert unter: Oracle, Cloud, Performance, ETL, ADWC

Bloom filters and parallel execution

Today I want to share with you another interesting example of solving performance problem which happened in the database used for Business Intelligence purposes. Users were complaining that the performance in kind of staging database (STGDB) was much...

Veröffentlicht 5 Jul 2018 15:10 von triBLOG

Gespeichert unter: Oracle, Troubleshooting, Performance, optimizer, statistics, Parallel Processing, dynamic sampling, parsing, bloom filter

Adaptive Plans at Kscope Community Service Day

Since Oracle 12c, the query optimizer is able to change execution plans at runtime. This feature is called “Adaptive Plans”. Something similar happened on the ODTUG Community Service Day at the Kscope conference in Orlando. The ODTUG Community Service...

Veröffentlicht 14 Jun 2018 22:51 von triBLOG

Gespeichert unter: Oracle, Performance, conferences, Oracle 12c

Playing with statistics modification hints

How often did you have the situation when performance problem disappeared just after refreshing object statistics? Of course it is nice to solve the problem quickly and simply, but is always better to understand what has exactly happened. Recently I had...

Veröffentlicht 7 Jun 2018 9:00 von triBLOG

Gespeichert unter: Oracle, Performance, hints, optimizer, statistics, execution plan

10: Office 365 Performance

Wenn wir über Office 365 Performance reden, sollten wir die folgenden Punkte beachten: SharePoint on-premise vs. Online Bandbreite CDN (Content Delivery Network) UI, ggf. eigene Lösungen, Masterpage Mit Browser Developer Tools analysieren Große Listen...

Veröffentlicht 18 Mai 2018 11:08 von SharePoint und Office 365 Blog

Gespeichert unter: Office 365, podcast, Performance

Using Temporary Tables for Complex Reports

Global temporary tables (or private temporary tables, if you use Oracle 18c) are a practical feature to be used for SQL queries with multiple steps, for example complex reports in a data warehouse. If you want to use them, some … Continue reading...

Veröffentlicht 15 Mai 2018 23:40 von triBLOG

Gespeichert unter: SQL, Oracle, Performance, ETL, DWH Architecture

Azure App mit PremiumV2 App Plan klonen

In Microsoft Azure gibt es den neuen App Plan PremiumV2. Neuste Funktionen sind vor allem bessere Performance der aktuellen CPU Generation, sowie SSD Speicher – yeah. Hört sich vielversprechend an, also gleich mal ausprobieren. Doch die erste Hürde...

Veröffentlicht 20 Apr 2018 8:33 von SharePoint und Office 365 Blog

Gespeichert unter: PowerShell, Azure, Skalierung, Performance, Azure Cloud Shell, App Service, Scale up, Klonen, App Service Plan, Resource Group

Keep Your SQL Simple (and Fast)

Complex SQL statements are hard to understand – not only for us, but for the query optimizer, too. Sometimes, it is a good idea to write a simpler SQL query to do the same work. Here a nice story about … Continue reading →...( read more...

Veröffentlicht 3 Apr 2018 22:01 von triBLOG

Gespeichert unter: SQL, Oracle, Performance

BI jobs performance degradation after Oracle 11.2.0.4 to 12.1.0.2 migration

If you have performance problems after migrating your BI databases from 11.2.0.4 to 12.1.0.2 or any other performance issue, you should not underestimate SQL Plan Notes, which can point you to the right direction or just let you understand what exactly...

Veröffentlicht 26 Mrz 2018 6:30 von triBLOG

Gespeichert unter: Migration, Oracle, Performance, optimizer, Parallel Processing, execution plan

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