Oracle 12c new features VARCHAR2 length maximum support up to 32767

Prior to the Oracle 12c version, the VARCHAR2 and NVARCHAR2 data types had a maximum length of 4000, with the extended maximum of 12c versions supported to 32767, or 32KB, and parameter Max_string_ The size is the maximum length of the extended data type that controls the extended datatype:

• Standard: Represents the length limit before 12c, that is, VARCHAR2 and NVARCHAR2 4 is 4000 Bytes,raw is 2000, and the system is standard by default;

• Extended: Represents 12c 32k strings new features, VARCHAR2, NVARCHAR2, raw maximum length is 32767, that is, 32KB

By default, the database parameter max_string_size is standard, so you need to modify the parameter value to extended, and the specific steps to configure the extended data type for the database are as follows:

1. 1> Close the DB instance, SHUTODNW immediate (if RAC is required to close all instances);

2. 2> starting the DB instance in upgrade mode: Startup upgrade;

3. 3> Modify parameter Max_string_size to EXTENDED (ALTER SYSTEM SET max_string_size = EXTENDED scope=spfile;);

4. 4> run @ $ORACLE _home/rdbms/admin/utl32k;

5. 5> Restart the DB instance.

This article is from the "Qytag (upspringing)" blog, so be sure to keep this source http://qytag.blog.51cto.com/6125308/1544916

Oracle 12c new features VARCHAR2 length maximum support up to 32767