Oracle Delete Query

Method 1 delete yourtable where [id] not in (select max ([id]) from yourtable group by (name + value) b on a.id = b.id where b.id ...

HBase as a subproject under Hadoop, the current development is more powerful, and traditional relational database Oracle to compare, both have advantages and disadvantages, we first look at a simple table. Data maintenance: For example, UPDATE, just insert a new record according to key value, the old version is still in, will be in the process of storefile merge delete data maintenance: Add and remove change is very convenient, directly modify the above simple list of hbase and Oracle the difference between the two, There are other details where there is no description, can be from above the right ...

Oracle as the world's largest relational database provider, in its product chain, also joined the NoSQL database, and this new database name is very domineering, called NoSQL db. Oracle's NoSQL Database, one of the components of the Big Data appliance, released on the Oracle Global Encyclopedia on October 4, is a component of the Big Data appliance, an integrated Hadoop, NoSQL Database, O ...

We want to do not only write SQL, but also to do a good performance of the SQL, the following for the author to learn, extract, and summarized part of the information to share with you! (1) Select the most efficient table name order (valid only in the Rule-based optimizer): The ORACLE parser processes the table names in the FROM clause in Right-to-left order, and the last table in the FROM clause (the underlying table driving tables) is processed first, In the case where multiple tables are included in the FROM clause, you must select the table with the least number of records as the underlying table. If...

As an outstanding representative of the Object relational database, Oracle is undoubtedly the most powerful. Whether it's the size of the database, the support of multimedia data types, the parallelism of SQL operations replication, or the security services, Oracle is much stronger than Sybase, Informix, Added to the latest version of the Oracle8.0.4 is to enhance the characteristics of this, but also introduced a number of new features, such as: Data partitioning (partitioning), Object-relational technology (objects relational T ...

Through the introduction of the core Distributed File System HDFS, MapReduce processing process of the Hadoop distributed computing platform, as well as the Data Warehouse tool hive and the distributed database HBase, it covers all the technical cores of the Hadoop distributed platform. Through this stage research summary, from the internal mechanism angle detailed analysis, HDFS, MapReduce, Hbase, Hive is how to run, as well as based on the Hadoop Data Warehouse construction and the distributed database interior concrete realization. If there are deficiencies, follow-up ...

Through the introduction of the core Distributed File System HDFS, MapReduce processing process of the Hadoop distributed computing platform, as well as the Data Warehouse tool hive and the distributed database HBase, it covers all the technical cores of the Hadoop distributed platform. Through this stage research summary, from the internal mechanism angle detailed analysis, HDFS, MapReduce, Hbase, Hive is how to run, as well as based on the Hadoop Data Warehouse construction and the distributed database interior concrete realization. If there are deficiencies, follow-up and ...

As a software developer or DBA, one of the essential tasks is to deal with databases, such as MS SQL Server, MySQL, Oracle, PostgreSQL, MongoDB, and so on. As we all know, MySQL is currently the most widely used and the best free open source database, in addition, there are some you do not know or useless but excellent open source database, such as PostgreSQL, MongoDB, HBase, Cassandra, Couchba ...

Logminer is an actual, useful analysis tool that Oracle has provided since 8i, which makes it easy to obtain specific content in Oracle Redo log files (archived log files), Logminer analysis tools are actually made up of a set of PL 　　SQL package and a number of dynamic views that can be used to analyze online logs and archive logs to obtain a database of past detailed, specific operations, very useful. 　　Why do you use Logminer? Mainly for the following reasons: When the database occurs ...

SQL is the standard computer language used to access and process databases. What is SQL? SQL refers to Structured Query language SQL gives us the ability to access database SQL is an ANSI standard computer language editor Note: ANSI, United States national standardization Organization SQL What can you do? SQL database-oriented query SQL can retrieve data from a database SQL can insert new records in a database SQL updatable database can be deleted from the database SQL to delete records SQL can create New ...