In this post I wrote down a fes Emacs shortcuts. Today I’m trying again, but a little more organised. A few defenitions: buffer : a representation of a file in memory of emacs. You edit a buffer frame : the whole of windows/menu’s/mini-buffer. On a graphical interface you can have multiple frames. On a text […]
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Today I needed to create an audit statement with a lot of users who are excepted from auditing. It looks somewhat like : audit policy <policy_name> except <comma separated list of users> For my requirement all Oracle Maintained account should be excepted from auditing. Following statement made it easy: spool policy_on.sql select ‘audit policy […]
Continue ReadingRecovering a database further then the last backupped controlfile
A question on forums.oracle.com asked: can we recover a database further in time then the time of backup of the last controlfile. Nice question…my gut feeling immediately says : YES we can. But…I do not have a proof of it, and one quick search on the internet did not supply a adequate answer. So…then I […]
Continue ReadingDistribution of values in a column
Distribution of data For calculating the right execution-plan Oracle often needs the distribution of values for a column. For an outlier value a index can easily be used. For a value that is present in half the rows a index might be less effective. For a similar exercise I needed the distribution of values myself. […]
Continue ReadingCreating an ACL
A very simple example of creating an ACL for a principal and a host: Creating the ACLS (qith the associated principal) itself. exec dbms_network_acl_admin.create_acl( acl=>’print_permissions.xml’, description=>’Gebruikt voor Print functionaliteit’, principal=>’APEX_230100′, is_grant=>TRUE, privilege=>’connect’); Associating a host to the ACL: exec dbms_network_acl_admin.assign_acl( acl=>’print_permissions.xml’, host=>’machine-name.domain.domain’, lower_port=>8010, upper_port=>8010); This is a starting point. You can go from here … […]
Continue ReadingAssembly and opcodes
Intro When a program is compiled (and linked) it will no longer contains readable lines of code. Instead it will consist of opcodes (operation codes). I would like to see whether I can find out what dome opcodes mean. You might say “just look at the intel or AMD manual and there you go”…but where […]
Continue ReadingOEM : No Data
This is reaaly memory for myself 🙂 We often encounter sql performance screens where OEM says “Unable to Retrieve Data” What we do : create a job (in OEM) that deploys Database Management PL/SQL packages In OEM main Menu Click Enterprise –> Job –> Library –> Select Job Type “Deploy Database Management PL/SQL Packages” –> […]
Continue ReadingOracle system statistics
Oracle System Statistics When I look at the system statistics I’m not really getting any wiser. There a re really a lot of statistics: SQL> select count(*) from v$sysstat; COUNT(*) ———- 2252 SQL> Above from a Oracle 21c instance. I do not want to see them all. I would like to see the change in […]
Continue Readingsar usage
I like to use the linux utility sar (system activity reporter (?)) I gives a fast and quite complete overview over the performance of a linux system. SAR has a lot of possibilitys. I just highlight a few of them to remember how the syntax is 🙂 CPU information of today oracle@lqas4342:~$sar Linux 4.18.0-425.13.1.el8_7.x86_64 (lqas4342.mod.nl) […]
Continue ReadingORAENV_ASK
Just a reminder I keep forgetting what the environment variable is called: ORA_ASKENV ORA_ENVASK ORAASK_ENV ORAENV_ASK This is _the_ variable: ORAENV_ASK=NO ORAENV_ASK=YES Happy scripting
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