Single IO operation integer-value database
The present disclosure relates to a system and methods of implementing an integer-value database using a single I/O operation. In particular, the present disclosure relates to methods of writing and reading information to a database using key/value pairs, including receiving, at a database management system, a value to be written to a database, the database including a plurality of segments stored on a storage medium, and assigning, by the database management system, an assigned key to the value based on keys previously used in the database. The method may further include storing, by the database management system, the assigned key and the value to a segment at a virtual end of the database, wherein the segment is identified in a mapping index by an offset and the mapping index identifies a first key in the segment, and returning the assigned key.
1. A computer-implemented method comprising:
receiving, at a database management system, a value to be written to a database, the database including a plurality of segments stored on a storage medium;
assigning, by the database management system, an assigned key to the value based on keys previously used in the database;
storing, by the database management system, the assigned key and the value to a segment at a virtual end of the database, wherein:
the virtual end of the database is located at a segment in the plurality of segments in the database that has been most recently modified,
the segment is identified in a mapping index by an offset and the mapping index identifies a first key in the segment, and
the assigning an assigned key to the value based on keys previously used in the database and the storing the assigned key and the value to a segment at a virtual end of the database are performed by the database management system in a single input/output operation on the storage medium; and
returning, by the database management system, the assigned key.
2. The computer-implemented method of claim 1 , wherein storing the assigned key and the value to the segment at the virtual end of the database includes:
determining, by the database management system, that a segment directly preceding a new segment does not have enough remaining storage space to store the assigned key and the value; and
creating, by the database management system, the new segment in the database, wherein the new segment is the segment at the virtual end of the database to which the assigned key and value are stored.
3. The computer-implemented method of claim 2 , further comprising:
filling, by the database management system, a remaining portion of the new segment with logical 0s.
4. The computer-implemented method of claim 2 , further comprising:
updating, by the database management system, the mapping index to include the assigned key as the first key in the segment and the offset identifying the new segment.
5. The computer-implemented method of claim 1 , wherein the assigned key and the keys previously used in the database are stored in increasing order in the storage medium.
6. The computer-implemented method of claim 1 , wherein the storage medium includes a hard disk drive.
7. The computer-implemented method of claim 1 , further comprising:
storing, by the database management system, the segment and the assigned key in memory; and
syncing, by the database management system, the segment in memory to the storage medium based on an event.
8. The computer-implemented method of claim 1 , wherein the offset indicates a relative placement of the segment with respect to the plurality of segments in the database.
9. A system comprising:
one or more processors; and
a memory storing instructions that, when executed by the one or more processors, cause the system to:
receive a value to be written to a database, the database including a plurality of segments stored on a storage medium;
assign an assigned key to the value based on keys previously used in the database;
store the assigned key and the value to a segment at a virtual end of the database, wherein:
the virtual end of the database is located at a segment in the plurality of segments in the database that has been most recently modified,
the segment is identified in a mapping index by an offset and the mapping index identifies a first key in the segment, and
the assigning an assigned key to the value based on keys previously used in the database and the storing the assigned key and the value to a segment at a virtual end of the database are performed by a database management system in a single input/output operation on the storage medium; and
return the assigned key.
10. The system of claim 9 , wherein to store the assigned key and the value to the segment at the virtual end of the database the instructions cause the system to:
determine that a segment directly preceding a new segment does not have enough remaining storage space to store the assigned key and the value; and
create the new segment in the database, wherein the new segment is the segment at the virtual end of the database to which the assigned key and value are stored.
11. The system of claim 10 , wherein the instructions cause the system to:
fill a remaining portion of the new segment with logical 0s.
12. The system of claim 10 , wherein the instructions cause the system to:
update the mapping index to include the assigned key as the first key in the segment and the offset identifying the new segment.
13. The system of claim 9 , wherein the assigned key and the keys previously used in the database are stored in increasing order in the storage medium.
14. The system of claim 9 , wherein the storage medium includes a hard disk drive.
15. The system of claim 9 , wherein the instructions cause the system to:
store the segment and the assigned key in memory; and
sync the segment in memory to the storage medium based on an event.
16. The system of claim 9 , wherein the offset indicates a relative placement of the segment with respect to the plurality of segments in the database.