cassandra - 无法更改/更改 cql cassandra 中列的数据类型

Question

CREATE TABLE mykespace.newtable (
    name text PRIMARY KEY,
    marks int,
    score float,
    value float,
    value2 blob
)

cqlsh:mykespace> alter table newtable alter value type int;
InvalidRequest: Error from server: code=2200 [Invalid query] message="Altering of types is not allowed"

cqlsh:mykespace> alter table newtable alter value2 type varint;
InvalidRequest: Error from server: code=2200 [Invalid query] message="Altering of types is not allowed"

无法更改数据类型，甚至 int 到 varint 和 float 到 int

Answer 1

从 Cassandra 3.10 和 3.0.11 开始，更改列数据类型的功能已被 CASSANDRA-12443 删除。 .

...because we no longer store the length for all types anymore, switching from a fixed-width to variable-width type causes issues. commitlog playback breaking startup, queries currently in flight getting back bad results, and special casing required to handle the changes.

这里最好的解决方法是删除现有列，并创建一个具有不同名称的新列(以避免提交日志重放的潜在问题)。比如:

ALTER TABLE mykeyspace.newtable DROP value;
ALTER TABLE mykeyspace.newtable ADD value_int int;