Parameter | Description |
CHS | Specifies whether to enable the cold and hot data separation feature. The following list describes how to specify this parameter: One long integer. Unit: seconds. If the gap between the partition data time and the current time is less than or equal to the value, the data is stored in L1. If the gap between the partition data time and the current time is greater than the value, the data is automatically dumped to L2.
Note If this parameter is set to 259200 , the cold and hot data is separately stored in two layers. If the gap between the partition data time and the current time is less than or equal to 259,200 seconds, the data is stored in L1. If the gap between the partition data time and the current time is greater than 259,200 seconds, the data is automatically dumped to L2.
Two long integers. Unit: seconds. Separate two long integers with a comma. Example: num0, num1 , where num0 must be less than num1 . If the gap between the partition data time and the current time is less than or equal to the first value, the data is stored in L1. If the gap between the partition data time and the current time is greater than the first value but less than or equal to the second value, the data is automatically dumped to L2. If the gap between the partition data time and the current time is greater than the second value, the data is automatically dumped to L3.
Note If this parameter is set to 259200, 864000 , the cold and hot data is separately stored in three layers. If the gap between the partition data time and the current time is less than or equal to 259,200 seconds, the data is stored in L1. If the gap between the partition data time and the current time is greater than 259,200 seconds but less than or equal to 864,000 seconds, the data is automatically dumped to L2. If the gap between the partition data time and the current time is greater than 864,000 seconds, the data is automatically dumped to L3.
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CHS_L1 | Specifies the storage type for L1. Format: 'CHS_L1'='storagetype=<desired storage type>' . Note If you do not specify this parameter when you create a table, the default storage type is Capacity storage. If you store data in the cloud, you can set the desired storage type to one of the following values: CAPACITY_CLOUD_STORAGE (default): stores data in Capacity storage.
STANDARD_CLOUD_STORAGE : stores data in standard storage.
PERFORMANCE_CLOUD_STORAGE : stores data in performance storage.
CLOUD_ARCHIVE_STORAGE : stores data in archive storage.
Note Archive storage is in internal preview. To use archive storage, contact Lindorm technical support (DingTalk ID: s0s3eg3).
If you store data in local disks, you can set the desired storage type to one of the following values: CAPACITY_CLOUD_STORAGE (default): stores data in Capacity storage.
LOCAL_SSD_STORAGE : stores data in local SSDs.
LOCAL_HDD_STORAGE : stores a large amount of data.
LOCAL_EBS_STORAGE : stores data in local ESSDs.
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CHS_L2 | Specifies the storage type for L2. CHS_L2 has the same format and valid values as CHS_L1. Note You must specify the CHS_L2 parameter. |
CHS_L3 | Specifies the storage type for L3. CHS_L3 has the same format and valid values as CHS_L1. Note If the CHS parameter is set to two long integers, you must specify the CHS_L3 parameter. |
CHS_EXP | Specifies how to obtain the partition data time. Format: toSec(${column0},${pattern0},${column1},${pattern1},...${columnN},${patternN}) . Where: columnN : the time partition field. Supported data types are INTEGER, LONG, STRING, and DATE.
patternN : the format of the corresponding time partition field. Valid values:
yyyy : year
MM : month
dd : day
HH : hour
mm : minute
toSec : the system function that calculates the maximum data time for the corresponding time partition. Examples:
Assume that the time partition fields are year, month, and day. For the year=2023, month=10, day=2 partition, toSec(year, yyyy) returns 2023-12-31 23:59:59 , toSec(year, yyyy, month, MM) returns 2023-10-31 23:59:59 , and toSec(year, yyyy, month, MM,day,'dd') returns 2023-10-02 23:59:59 . Assume that the time partition field is date. For the date=2023-10-02 partition, toSec(date, yyyy-MM-dd) returns 2023-10-02 23:59:59 .
The Lindorm compute engine obtains the maximum partition data time returned from the CHS_EXP parameter and dumps the partition data to the corresponding storage based on the value specified by the CHS parameter. |