By default, YugabyteDB presplits a table in ysql_num_shards_per_tserver * num_of_tserver shards.
We can display the number of tablets for a table using the yb_table_properties function.
yugabyte=# CREATE TABLE test (c1 INT PRIMARY KEY, c2 VARCHAR);
CREATE TABLE
yugabyte=# SELECT * FROM yb_table_properties('test'::regclass);
num_tablets | num_hash_key_columns | is_colocated | tablegroup_oid | colocation_id
-------------+----------------------+--------------+----------------+---------------
6 | 1 | f | |
(1 row)
The SPLIT INTO clause can be used to override the ysql_num_shards_per_tserver setting on a per-table basis.
yugabyte=# DROP TABLE test;
DROP TABLE
yugabyte=# CREATE TABLE test (c1 INT PRIMARY KEY, c2 VARCHAR) SPLIT INTO 12 TABLETS;
CREATE TABLE
yugabyte=# SELECT * FROM yb_table_properties('test'::regclass);
num_tablets | num_hash_key_columns | is_colocated | tablegroup_oid | colocation_id
-------------+----------------------+--------------+----------------+---------------
12 | 1 | f | |
(1 row)
Have Fun!