Change private interconnect network interface in Database 12c CRS GPnP
Submitted by Ewan on
How to start CRS when the private interconnect's netmask has changed. This HowTo will describe how to update the OLR with the new netmask.
Classifications:
You are here
Databases
Recover from lost OCR disk group in Oracle Database 12c
Submitted by Ewan on
How to recreate a lost OCR ASM disk group from scratch. This HowTo applies to Database 12c RAC. We will rebuild the disk group, restore the OCR, replace the voting disks, and recreate the ASM parameter and password files.
Oracle Database 12c: Flex ASM enable an existing cluster
Submitted by Ewan on
This HowTo demonstrates migrating a RAC cluster to Flex ASM from 'traditional' ASM.
The prerequisites are that the OCR files, ASM parameter file and ASM password file are stored in an ASM disk group with asm.compatible set to at least 12.1. We will confirm the ASM cluster mode before we begin and after we have finished.
Oracle Database 12c IPv6 enabled CRS RAC (Grid Infrastructure)
Submitted by Ewan on
Oracle Database 12c Release 1 fully supports IPv6. Here is how to add IPv6 support to VIPs and SCANs in a 12c RAC cluster. The VIPs, SCANs and their listeners will support both IPv4 and IPv6 and addresses from both families will relocate between RAC nodes as normal. It is only assumed that the servers already have a host IPv6 address assigned via auto-configuration.
Mapping UK crime data HowTo
Submitted by Ewan on
We will create a database and populate it with UK streets and incidents of street crime. We will then plot the crimes on an interactive map for further analysis.
We will create a PostgreSQL PostGIS database on the local machine. Eventually all our spatial data will be stored here.
Classifications:
Places:
Capacity trending graphs/charts in Oracle Grid Control
Submitted by Ewan on
Below I will annotate an example using SQL to extract and chart some tablespace trending data using GNU Plot.
Oracle's Grid Control collects, stores, and manages historical metric data for hosts, databases, and all sorts of targets. This data is difficult to retrieve, especially the historical data. Creating a report in Grid Control results in a small bitmapped image. If you need, say, a year of CPU data, this small bitmap is difficult to interpret.
If the data is extracted from Grid Control's Oracle Management Service (OMS) then graphically representing the data can also be performed externally. One such tool that can be used to graph the data is GNU Plot.
Classifications:
Monitoring GoldenGate replicat performance using 'flashback query'
Submitted by Ewan on
By using a checkpoint table in the OGG replicat database, you can retrospectively review the replicat's lag using flashback query (with some limitations if you do not utilise a heart beat table).
Picture the scenario. You receive observations that the Oracle GoldenGate (OGG) replicat system that you are responsible for had fallen behind overnight and all overnight processing was performed against incorrect data. What do you do? Perhaps the observation was erroneous. How can you demonstrate this?
Classifications:
'ACID' compliant NoSQL document database
Submitted by Ewan on
Following on from FoundationDB's graph store, they are now proposing a document store. Again, there is emphasis on 'ACID' compliance. So, unlike most other newcomers to the database scene, their database will support the protections familar to RDBMS database administrators. The database should be protected from interference and corruption, and benefit from protection of saved transactions.
Classifications:
Oracle Database 12cR1 released
Submitted by Ewan on
Oracle have released Database 12c Release 1 (version 12.1.0.1.0). Of particular note is the multi-tenant database facility. Each server has one container database (CDB), and that CDB may have one or more pluggable databases (PDBs).
Classifications:
MapReduce introduction (Linux Journal)
Submitted by Ewan on
Linux Journal has published a simple to understand introduction to MapReduce using Hadoop. Definitely worth a read if you need an introduction.
Pages
