• About Me

    Maxwell Miranda
    Oracle DBA Consultant.
  • Category

  • Archives

  • My Blog Calendar

    November 2009
    M T W T F S S
    « Oct   Jan »
  • RSS Oracle Feeds

    • MySQL Error: Checking for corrupt, not cleanly closed and upgrade needing tables
      Hi, I just reset mysql's password to be empty. It's a virtual machine so I don't care of the security. After the mysqld restart I got this error "Checking for corrupt, not cleanly closed and upgrade needing tables." I also did the following to repair the tables and the error is still the same. root@plesk:/var/lib/mysql/mysql# myisamc […]
    • Anyone home?
      Bueller? Bueller?
    • Database Replay
      Hi All, I have a question about the database replay feature. On the test system, before I begin preprocessing how do I make sure the test database = prod database before capture? Is this a full export/import or just a schema export/import? Thanks, Kathy
    • Oracle JSON parsing?
      Here is my JSON stored in a CLOB column: Code: --------- select upJSON from myLocations; {"values":[ {"nameValuePairs":{"upJSON":"{\"mResults\":[0.0,0.0],\"mProvider\":\"fused\",\"mDistance\":0.0,\"mAltitude\":0.0}","id":"1","updated": […]
    • Foreign Keys deferred vs disabled
      Here is my observation regarding deferred foreign keys which I am not able to understand: - We have 3 tables : TP1, TC1 & TC2. TC1 and TC2 have foreign keys pointing to TP1 and foreign keys are defined as DEFERRED. - We load huge amounts of data to these tables once a week and the insert takes unusually long time. This is how we insert: (Case 1) step 1: […]
      Hi Friends, While analysing the AWR report of Oracle 11g, In PGA TARGET Advisory i found low est_pga_cache_hit_percentage at size_factor =1. If I increase the PGA_AGGREGATE_TARGET size will it improve the performance of the queries that accessing SORT/MERGE/HASH paths. or Should i found the queries accessing SORT/MERGE/HASH paths and tune them? Which will be […]
    • Oracle Performance
      Hello Please I am actually using a new server on Linux Redhat with 32G (64 bits) . I need some advice to increase performance since my rman takes Now 2 hours instead of 1 hour before when I was on 16G See below pfile details Code: --------- rwddb.__db_cache_size=1577058304 rwddb.__java_pool_size=33554432 rwddb.__large_pool_size=16777216 rwddb.__shared_pool_s […]
    • New to DBA
      Hi all, Hope this is the right place to post this question. I recently joined a program that prepares students to become DBA's. Its a six month program, roughly. It's every weekend sat-sun, 4-7 P.M. I wanted to attach our course schedule and get some feedback from you guys to see if the topics covered in this course would prepare me for an actual j […]

A little additional info on hc_ files:

“Q1: What is the $ORACLE_HOME/dbs/hc_.dat file?
A1: The $ORACLE_HOME/dbs/hc_.dat is created for the instance health check monitoring. It contains information used to monitor the instance health and to determine why it went down if the instance isn’t up. The file will be recreated at every instance startup.

Q2: What happens if the $ORACLE_HOME/dbs/hc_.dat file is deleted?
A2: Per Bug 4645405 UNABLE TO START DB – ORA-7445 [KSIHSMRINI()+152] [SIGBUS],
if you replace the file with an empty “dummy” copy, you will get an ORA-7445 error. Therefore, if the file gets deleted on the fly while the database is up, or if the file is replaced with a 0 byte file, simply delete the file and restart the database. The file will be correctly recreated at the next database startup.”

About these ads

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

%d bloggers like this: