ADLS Gen 2 Delta Tables memory allocation

[kkumar]

if i mount a gen2(ADLS 1) to another gen2(ADLS2) account and create a delta table on ADLS2 will it copy the data or just create something link External table.

i don't want to duplicate the the data.

[youssefmrini]

Hey You can't have have nested mounts.

[Pat]

Hi @keerthi kumar​ ,

so basically you can CREATE EXTERNAL TABLES on top of the data stored somewhere - in your case ADLS. Data won't be copied, it will stay where it is, by creating external tables you are actually storing the metadata in your metastore (hive, unity catalog) - where the data is stored, table schema, partitions, etc.

Storing data and being able to query it with different engines it's called decoupling. Decoupling storage from compute allows you to manage cost of storage and compute separately.