- Add two new types to stream load boker load: **csv_with_names** and **csv_with_name_sand_types**
- Add two new types to export: **csv_with_names** and **csv_with_names_and_types**
Add a new column-type to speed up the approximation of quantiles.
1. The new column-type is named `quantile_state` with fixed aggregation function `quantile_union`, which stores the intermediate results of pre-aggregated approximation calculations for quantiles.
2. support pre-aggregation of new column-type and quantile_state related functions.
In some scenarios, users cannot find a suitable hash key to avoid data skew, so we need to provide an additional data distribution for olap table to avoid data skew
example:
CREATE TABLE random_table
(
siteid INT DEFAULT '10',
citycode SMALLINT,
username VARCHAR(32) DEFAULT '',
pv BIGINT SUM DEFAULT '0'
)
AGGREGATE KEY(siteid, citycode, username)
DISTRIBUTED BY random BUCKETS 10
PROPERTIES("replication_num" = "1");
Co-authored-by: caiconghui1 <caiconghui1@jd.com>
add a flag of fuzzy_parse, if the json file all object keys are the same and has same order, we only need to parse the first row, and then use index instead key to parse value
This CL mainly changes:
1. Reorganized the code logic to limit the supported json format to two, and the import behavior is more consistent.
2. Modified the statistical behavior of the number of error rows when loading in json format, so that the error rows can be counted correctly.
3. See `load-json-format.md` to get details of loading json format.
