Author: admin

PL/SQL Oracle / SQL Server

Binary Search

One of the most interesting algorithms of research is binary search algorithm. This is the fastest algorithm (algorithm of binary trees apart) to search a data inside a group of elements. In fact it runs in a worst log2(x) comparisions before to find (or not) the data. The only prerequisite is : the set of elements where to search the data must be sorted. Below an example of this algorithm. int binary_search( int arr[], int tot_el, int data ) { /* Declaration and initialization of variables */ int el = 0; int me = 0; int count = 0; /*...

PL/SQL Oracle / SQL Server

Record data type

In Pl Sql exists a lot of data types : varchar2, number, float, double, boolean, etc, but it may happen that you want to use a structure that contains several types of data, we call it Record type. It’s a simply a new data type. Record type is formed by a group of one or more columns with own name and data type. To create Record type have to use the keyword TYPE so to instruct the compiler about this new data type. There are two ways to create it , the first is at “database level” which can be...

Oracle Database

Oracle 12C – Password File in ASM

Prior to Oracle Database 12c, the password file was always located under $ORACLE_HOME/dbs file structure, even for RAC instances and for RAC ASM cluster. For RAC the DBA had to managed to keep the password file in sync on each node. Now , in Oracle 12c, it is possible to store the password file on ASM. This means a shared password file for Oracle RAC databases , it is shared for all instances in the cluster. The command utility to create the password file is still the same: “orapwd” Oracle 11g file – name of password file (required), password –...

Oracle Database / Oracle VM

ORACLE: OVMM 3.4.2

PART 1 LINK Oracle VM 3-4-2 Oracle VM Manager 3.4.2 supports current and previous Oracle VM Server releases. Part 2 You can use Oracle VM Manager 3.4.2 to manage Oracle VM Server Release 3.4.x, 3.3.x, 3.2.10, or 3.2.11. If Oracle VM environment consists of Oracle VM Manager Release 3.4.2 and one or more instances of Oracle VM Server at a different release, you should review the list of supported and unsupported operations and features, as follows: Supported Operations Oracle VM supports most common operations when using Oracle VM Manager to manage an instance of Oracle VM Server that is at...

Oracle Database

DB_ULTRA_SAFE parameter

DB_ULTRA_SAFE is a new parameter introduced in 11g. It provides an integrated mechanism to offer protection from various possible data corruptions. and provides critical high availability benefits for Oracle Database. Setting DB_ULTRA_SAFE initialization parameter will configure the appropriate data protection block checking level in the database. It will control DB_BLOCK_CHECKING, DB_BLOCK_CHECKSUM, and DB_LOST_WRITE_PROTECT. DB_BLOCK_CHECKING controls whether or not Oracle performs block checking for database blocks. DB_BLOCK_CHECKSUM determines whether DBWn and the direct loader will calculate a checksum and store it in the cache header of every data block when writing it to disk. DB_LOST_WRITE_PROTECT enables or disables lost write detection....

Oracle Database / Oracle Database 12 c

Oracle12C : Database Firewall

The Oracle Database Firewall enables organizations to protect their databases from internal and external attacks. Oracle Database Firewall allows unauthorised SQL traffic on the network to be monitored and blocked before reaching the database. Database Firewall for Security and Compliance Oracle Database Firewall monitors and enforces normal application behavior in order to avoid the increasingly sophisticated Data Centre attacks that can lead to unauthorised external access. The security control of Oracle Database Firewall helps to prevent malicious activity such as SQL injection and application bypass from reaching the database. Next-Generation Network-based Database Security The grammar of the SQL statements being...

Oracle Database / Oracle Database 12 c

ORACLE 12C: Data Migration Assistant

The Database Migration Assistant for Unicode (DMU) provides a good solution for migrating databases from legacy character sets to the Unicode character set. It is shipping with Oracle Database 12c Rel.1 and becomes the officially supported method for migration to the Unicode character set. Database Character Set Scanner (CSSCAN) and CSALTER utilities are removed from the database installation and have been desupported. DMU also supports migrating selected prior database releases of 10.2, 11.1 and 11.2. Oracle DMU 2.1, released in May 2015, supports a near-zero downtime migration model in conjunction with the Oracle GoldenGate replication technology. Using DMU2.1 and GoldenGate...

Oracle Database

Oracle: DBMS_COMPARISON package

An interesting feature for Oracle 11g is DBMS_COMPARISON package which planned to use compare data within two schemas or between database`s schema. To use DBMS_COMPARISON you have to grant. If you connected as SYSDBA you already have had grant to execute. Other users need execute grants on DBMS_COMPARISON and that user will need to be granted execute catalog role too. Note: The database character sets must be the same for the databases that contain the database objects being compared. For all scan modes to be supported by the DBMS_COMPARISON package, the database objects must have one of the following types...

Oracle Database

Compress table

Scenery: Mass distribution of rich and multimedia content over the Internet, made possible through advancements in broadband technologies, also contributes to the growth in overall data volume. The enormous growth in the volume of data that needs to be retained online makes storage one of the biggest cost elements of most IT budgets. The compression clause can be specified at the tablespace, table or partition level with the following options: NOCOMPRESS – The table or partition is not compressed. This is the default action COMPRESS – This option is considered suitable for data warehouse systems OMPRESS FOR ALL OPERATIONS – This option is...

Oracle Database

ORACLE – VM 3.4.2

During Oracle OpenWorld 2016, the company has announced new version (3.4.2) of their virtualization platform Some of the key new features that have been delivered include: Oracle VM Manager support for previous Oracle VM Server releases: – Manage Oracle VM Server for x86 – 3.4.x, 3.3.x or 3.2.10/11 releases. – Manage Oracle VM Server for SPARC – Agent 3.4.x or 3.3.x releases. Support for NVM Express (NVMe) devices: – Discover NVMe devices and present them to Oracle VM Manager – NVMe devices can be used to store virtual machine disks or create storage repositories. Extended SCSI functionality available for virtual...