extracting single database from a [large] mysqldump or pg_dump

MySQL:

extracting the whole database:

sed -n '/^-- Current Database: `databaseName`/,/^-- Current Database: `/p' /path/to/the/fill/dump.sql  > output.sql

single table:

sed -n '/^CREATE TABLE `tableName`/,/^\-\- Table structure for table /p' /path/to/the/fill/dump.sql  > output.sql

[via this blog]

PostgreSQL:

pv dump.sql | perl -ne 'print if /^COPY public.name_of_the_table/ .. /^\\\.$/' > out.sql

[ via https://stackoverflow.com/a/62289905 ]