Geoandmebaasid ja indeksid
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Date
2013
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Publisher
Tartu Ülikool
Abstract
Käesoleva bakalaureusetöö eesmärgiks oli uurida andmebaasi indeksite ja
geoindeksite andmestruktuure ja need esitleda emakeeles. Ühelt poolt tegin seda
leiduvate materjalide vähesuse tõttu ja teiselt poolt, et tutvustada inimestele, kuidas
indeksid andmebaasihaldussüsteemides töötavad. Kolmandaks põhjuseks tooksin
enda huvi ja neljandaks soovi luua õppematerjal antud teemast huvituvale inimesele.
Antud töö esimeses osas vaadeldi andmebaase ja indekseid. Pikemalt keskenduti iga
indeksitüübi andmestruktuurile. Eraldi peatuti ka tööpõhimõtetel ja toodi juhiseid
indeksite kasutamiseks.
Teises osas vaadeldi lähemalt geoandmebaase ja geoindekseid. Antud peatükis
kirjeldati põhjalikult ka iga indeksitüübi andmestruktuure ja viimaste paremaks
mõistmiseks lisati ilmekad illustratsioonid.
Bakalaureusetöö kolmandas peatükis võrreldi kolme andmebaasihaldussüsteemi
opereerimist kattuvuspäringute sooritamisel ja indeksite mõju tulemustele. Võrreldi
ka ajalist erinevust indeksiga ja indeksita päringute vahel, tehti põhjalik analüüs
ning võeti tulemused kokku.
Püstitatud eesmärgid said bakalaureusetöö lõpuks täidetud. Sain isiklikult palju uusi
teadmisi juurde ning mõistan andmebaaside käitumist paremini. Enda jaoks
huvitavaid tulemusi sain just jõudluskatsetest indekseeritud ja indekseerimata
andmete vahel. Rahule jäin ka sisuga, sest tööd saab kasutada õppematerjalina ka
täiesti teemavõõras inimene, sest usun, et see on piisava detailsusega, ent arusaadav.
Antud bakalaureusetöö edasiarendamiseks on võimalik uurida PostgreSQL, PostGIS
ja GEOS paketi lähtekoodi ning leida põhjus tulemustes kajastunud kiirusele.
Eesmärgiks lähitulevikus on parandada metsaeraldiste vead Oracle andmebaasis
ning leida töös kajastamata jäänud tulemused.
The goal of the thesis was to examine data structures of indices and geoindices and to present it in my mother tongue. On one hand, I did it because of the scarcity of material and on the other hand to give people better understanding how indices work in database management systems. The first chapter of the thesis focused on databases and indices. Data structures of each index type were described in more detail. In addition the operating principles of indices were introduced and tips how to use indices correctly were given. The second chapter focused on geodatabases and geoindices. Data structures of these index types were introduced and lots of expressive illustrations were included. The third chapter compared three database management systems on spatial queries and described how indices influenced these results. The comparison between the time and speed of indexed data and non-indexed data was presented. Results were analyzed and summarized. For future work it is possible to research the source code of PostgreSQL, PostGIS and GEOS package and to find the cause of the speed reflected in the results.
The goal of the thesis was to examine data structures of indices and geoindices and to present it in my mother tongue. On one hand, I did it because of the scarcity of material and on the other hand to give people better understanding how indices work in database management systems. The first chapter of the thesis focused on databases and indices. Data structures of each index type were described in more detail. In addition the operating principles of indices were introduced and tips how to use indices correctly were given. The second chapter focused on geodatabases and geoindices. Data structures of these index types were introduced and lots of expressive illustrations were included. The third chapter compared three database management systems on spatial queries and described how indices influenced these results. The comparison between the time and speed of indexed data and non-indexed data was presented. Results were analyzed and summarized. For future work it is possible to research the source code of PostgreSQL, PostGIS and GEOS package and to find the cause of the speed reflected in the results.