Research of LOB data compression and read-write efficiency in oracle database

Abstract

Aiming at the problems of huge storage space, low exchange speed and low read-write speed of the current specific oracle database, the read-write speed and exchange speed tests are performed on the compressed and uncompressed Clob and Blob data by three compression algorithms, including Bzip2, Gzip and GzipIO respectively. The read speed test is performed by the direct read, substr read, and substr+threadPool read techniques. The results show that: (1) Blob is superior to Clob in terms of storage, exchange, or read-write speed; (2) For the specific database, Blob+Gzip is the optimal storage structure of the minute and second data. The read-write speed is greatly improved, and the overall capacity of the database is reduced to 7% (or less). The exchange rate of the second data is at least 7.89 times of the present rate, and the station data can be exchanged to the disciplinary center within 2–3 hours (currently 1.5 days); (3) The simplest and most widely used direct read method by software developers has poor database read efficiency, while the substr+threadPool technique shows higher database read efficiency no matter for Clob or Blob, for compressed or uncompressed, which brings a leap-forward improvement in the read speed of LOB data. The results of this paper are of high reference significance to the LOB data storage design and software development.