Need database suport in simple embedded Environment

[chethankp]

I need to implment database in simple Embedded environment using normal C functions . I dont have more memory to freely implemnet all the behviour of sqllite kind of database .. I need a simple implementation which can provide key-value kind of storing/modifying for diffrent application on single Embedded Environment .. Like two Functions of my application can use the file called file.db to store and modify their data .. Can some body help ho to have a better design .. 1. One kind of data need to store

typedef struct Device
{
char Nname[20];
int type;
int ctype ;
}Network;
2. Second kind of data need to store

typedef struct Usage
{
char Nname[20];
int StartTime;
int Endtime;
int interfaceType;

}UsagePattern;
Third Kind of data need to store

typedef struct Endpoint
{
char IpaddressSrc[20];
char IpaddressDst[20];
int srcPort;
int dstPort;

}endPoint;
what kind of data base design is suggestable to store this in file using C simple function.