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How much maximum RAM is used by Oracle XE ?

Hi,

We are running Oracle XE on a server with 48 GB RAM out of which only 24GB is usable. I read that Oracle XE uses 2GB RAM even if more is available. This means we do not get performance increase from our server right?

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Answers

  • L. Fernigrini
    L. Fernigrini Data Engineer Sr Consultant Member Posts: 3,858 Silver Crown
    Answer ✓

    XE is the free version of Oracle and has a limit to use 2Gb of RAM and 12 Gb of storage (although you can store more data than previous XE versions since you can enable compression). It also uses only 2 CPU cores:


    If you need to use more RAM or Storage or CPUs in a production environment, then XE is not the edition for you,

  • EdStevens
    EdStevens Member Posts: 28,778 Gold Crown

    In addition to spot-on comment by @L. Fernigrini , your question assumes that more memory means better performance. But if your performance bottleneck is something other than a lack of available memory, then throwing a whole terrabyte of memory at it will not improve performance one whit.

    L. Fernigrini
  • User_C3D23
    User_C3D23 Member Posts: 2 Green Ribbon

    Thank you for both answers. It confirmed my understanding. I am transforming flat file data into rdbms, for example I am running procedure on a temp table with about 1 million records to convert dates, find certain data from other tables and inserting into actual table. This takes lot's of time even though I do it in chunks. The procedure is able to process about a thousand records per second but slows down later. That's why I wanted to know that in case of Oracle xe, increasing RAM will not be useful.

  • EdStevens
    EdStevens Member Posts: 28,778 Gold Crown

    You should approach this just like any other performance tuning issue. Instead of jumping to some silver-bullet conclusion about what might resolve the issue, perform some actual performance analysis and see exactly where the bottleneck is. If you need help on how to perform that analysis, there is a whole forum space, here, dedicated to performance issues.

  • cormaco
    cormaco Member Posts: 1,959 Silver Crown
    The procedure is able to process about a thousand records per second but slows down later.
    

    That procedure might be very inefficently written.

  • EdStevens
    EdStevens Member Posts: 28,778 Gold Crown
    edited Jan 15, 2022 3:18PM

    That procedure might be very inefficently written.

    Indeed.

    I always refer back to a section in the Oracle7 Server Tuning, Release 7.3.3. Yes, 7.3. And it still applies.


    Prioritized Steps of the Tuning Method


    The recommended method for tuning an Oracle database prioritizes steps in order of diminishing returns: steps which have the greatest impact on performance are listed first. For optimal results, therefore, tackle tuning issues in the order listed: from the design and development phases through instance tuning.


    Step 1: Tune the Business Rules

    Step 2: Tune the Data Design

    Step 3: Tune the Application Design

    Step 4: Tune the Logical Structure of the Database

    Step 5: Tune the SQL

    Step 6: Tune the Access Paths

    Step 7: Tune Memory Allocation

    Step 8: Tune I/O and Physical Structure

    Step 9: Tune Resource Contention

    Step 10: Tune the Underlying Platform(s)

    'Worrying about server memory comes under step 10 -- the very last/least priority.