TTL documentation

[Enrico Cavallin <ca...@gmail.com>]

Hi all,
I cannot understand what this statement means:

<<Use CREATE TABLE or ALTER TABLE to define the default_time_to_live
property for all columns in a table. If any column exceeds TTL, the entire
table is tombstoned.>>

in https://docs.datastax.com/en/dse/6.7/cql/cql/cql_using/useExpire.html

I have already done some tests with TTL set on columns, rows and default on
table and all seems in line with the logic: an already written row/value
maintains its TTL unless updated; a new default_ttl will not change TTL on
already existing rows.
What do they mean with "If any column exceeds TTL, the entire table is
tombstoned" ?

Thank you,
Enrico

Re: TTL documentation

[Jeff Jirsa <jj...@gmail.com>]

Those aren’t the project docs, they’re datastax’s docs, but that line makes no sense.

I assume they meant that once a column reaches its TTL it is treated as a tombstone. That’s per column and not the entire table. 

-- 
Jeff Jirsa


> On Feb 1, 2019, at 1:47 AM, Enrico Cavallin <ca...@gmail.com> wrote:
> 
> Hi all,
> I cannot understand what this statement means:
> 
> <<Use CREATE TABLE or ALTER TABLE to define the default_time_to_live property for all columns in a table. If any column exceeds TTL, the entire table is tombstoned.>>
> 
> in https://docs.datastax.com/en/dse/6.7/cql/cql/cql_using/useExpire.html
> 
> I have already done some tests with TTL set on columns, rows and default on table and all seems in line with the logic: an already written row/value maintains its TTL unless updated; a new default_ttl will not change TTL on already existing rows.
> What do they mean with "If any column exceeds TTL, the entire table is tombstoned" ?
> 
> Thank you,
> Enrico