How to correct an identity column sequence after import

Thanks to the authors behind Grassroots-oracle for sharing this trick.

I finished an import of a table with an identity column, and for some reason, the sequence started to hand out number at the bottom of the range, although it had reached 10632546 in the source table.

My table's DDL:

CREATE TABLE MYTABLE
(
  MYID                   NUMBER GENERATED ALWAYS AS IDENTITY ( START WITH 21 MAXVALUE 9999999999999999999999999999 MINVALUE 1 NOCYCLE CACHE 20 NOORDER NOKEEP NOSCALE) NOT NULL,
  EVENT_TYPE             VARCHAR2(75 BYTE)      NOT NULL,
  SOURCE                 VARCHAR2(50 BYTE)      NOT NULL,
  FORMAT                 VARCHAR2(75 BYTE)      NOT NULL,
  EVKEY                  VARCHAR2(60 BYTE)      NOT NULL,
  TITLE                  VARCHAR2(40 BYTE)      NOT NULL,
  TIMESTAMP              TIMESTAMP(6)           DEFAULT current_timestamp,
  DOCUMENT               CLOB                   NOT NULL,
  FILEREF                VARCHAR2(200 BYTE)     DEFAULT 'some text' NOT NULL,
  TRANNUM                NUMBER
)
LOB (DOCUMENT) STORE AS SECUREFILE (
  TABLESPACE  LOB_DATA
)
TABLESPACE DATA;

After import, the developers tested an insert and the row was inserted with MYID set to 1.

There is no Primary Key on the table, which I pointed out to the developers.

The sequence name was ISEQ$$_88174, and the query below returned the number 2 after import in the destination database:

select "ISEQ$$_88174".nextval
from dual;

To "start where the sequence left off" in the source database, all I had to do was to execute:

ALTER TABLE MYTABLE
MODIFY (MYID  GENERATED ALWAYS AS IDENTITY ( START WITH LIMIT VALUE) );

If I queried the sequence's next value now, it had changed from 2 to 10632547.

I then checked the maximum value of the column:

select max(MYID) from MYTABLE;

And it returned 10632546, in other words, the next value would be the current max value + 1.