Oracle 参数 BLOCKCHAIN_TABLE_MAX_NO_DROP 官方解释，作用，如何配置最优化建议
本站中文解释
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BLOCKCHAIN_TABLE_MAX_NO_DROP_TABLE是一个可以限制Oracle不允许用户运行DROP TABLE语句而主动删除表的参数，它默认值为0，表示不限制删表操作。如果希望禁止用户删表的行为，可以设置该参数的值大于0，比如设置为1，即允许0-1号表正常操作，而禁止对2号及以后的表进行删除操作。
在Oracle中，可以通过ALTER SYSTEM语句来修改BLOCKCHAIN_TABLE_MAX_NO_DROP_TABLE参数，具体格式如下：
ALTER SYSTEM SET BLOCKCHAIN_TABLE_MAX_NO_DROP_TABLE=x SCOPE=MEMORY;
其中x表示需要设置的值，可以根据具体情况进行修改，记住要用SCOPE=MEMORY参数，以便把修改立即生效，且不会在重启数据库时失效。
官方英文解释
BLOCKCHAIN_TABLE_MAX_NO_DROP lets you control the maximum amount of idle time that can be specified when creating a blockchain table. The idle time represents the length of time the table must be inactive before it can be dropped. When explicitly set by a user, the only value allowed for this parameter is 0.
| Property | Description |
|---|---|
|
Parameter type |
Integer |
|
Default value |
None |
|
Modifiable |
|
|
Modifiable in a PDB |
Yes |
|
Range of values |
None or |
|
Basic |
No |
|
Oracle RAC |
The same value must be used on all instances. |
When creating a blockchain table with the SQL statement CREATE BLOCKCHAIN TABLE, you can specify the clause NO DROP UNTIL number DAYS IDLE. This clause specifies the number of days the table must be inactive before it can be dropped, that is, the number of days that must pass after the most recent row insertion before the table can be dropped.
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If
BLOCKCHAIN_TABLE_MAX_NO_DROPis set to0, then when a user creates a blockchain table and specifies theNODROPUNTILnumberDAYSIDLEclause, the value ofnumbermust be0:CREATE BLOCKCHAIN TABLE ... NO DROP UNTIL 0 DAYS IDLE ...This allows the blockchain table to be dropped at any time, regardless of how long the table has been inactive.
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If
BLOCKCHAIN_TABLE_MAX_NO_DROPis not set, then when a user creates a blockchain table and specifies theNODROPUNTILnumberDAYSIDLEclause, any number value can be specified fornumber.
See Also:
Oracle Database SQL
Language Reference for information about the CREATE TABLE statement
