On the contrary if performance really matters one would go with a dynamic solution in order to minimize the overhead of allocating a very large memory segment and using only a small portion of it. A static solution is not optimized in terms of memory management.

Yes a linked list should be used for dynamic cases as it allows searching the database and removing entries from it whereas a sequential list like the one used by the o/p allows only insertions in the form of appends.

Why would you need to expand a static array. Don't you think that's an oxymoron? If you need to expand an array it becomes dynamic by default. The only case where that solution won't work is the gray scenario you suggested where the number of allocated entries is more than the used ones; as in the case below where the array has 10 entries allocated and only 5 are used.

Code:

static struct empRec employee[10] =
{
     {"Peter North","4B-208",35400,{10,11,1983}},
     {"John Musa","2B-118",25400,{07,10,1993}},
     {"Paula Jeminova","1A-506",18700,{02,1,1990}},
     {"Patricia Silver","6C-123",52100,{14,21,2000}},
     {"Robert mill","4D-318",42100,{01,19,2008}}
}

You won't need double level of indirection...the memory returned by malloc() will be assigned to a pointer to an object of type struct empRec that is a single level of indirection. My earlier post showed that scenario.

Imho the only case which it doesn't fit is the gray case you proposed where the number of allocated entries is more than the ones used.