ORA-00371: not enough shared pool memory, should be at least 16341008384 byte

SQL> startup pfile=initaux.ora  ORA-00371: not enough shared pool memory, should be at least 16341008384 bytes

Whenever we start an oracle database instance, it requires memory to allocate some memory components of the SGA so that instance could serve the database and database sessions. If we do not specify size of memory components, we might face errors during instance startup. sga_target is the basing parameter to specify before we start an instance and other memory components like shared pool, buffer cache, or log buffer cache are allocated from the memory allocated to SGA.

ORA-56747: invalid value ... for parameter sga_target

SQL> alter system set sga_target=4257m;  alter system set sga_target=4257m  *  ERROR at line 1:  ORA-02097: parameter cannot be modified because specified value is invalid  ORA-56747: invalid value 4463788032 for parameter sga_target; must be smaller  than parameter sga_target of the root container