1. Python version: 2.7
2. Database version: PostgreSQL 9.6+, Oracle 11.2+
3. Database schema:
    a). twitter1: id, text, coordinate
    b). twitter2: id, text, x,y
    c). yelp: id, reviews, coordinate
    d). uber: datetime, x, y, base
4. LIMITlib.py: most of the interfaces used in the experiments. Please see the comments of each function.
5. VAS.py: implemented two methods of VAS, points from data file and points in database.
6. npVAS.py: implemented VAS in numpy, a popular python package.
7. myMSE.py and myEMD.py: implemmented the two algorithms of comparing the similarity of two images.
9. ReqDB.py: send qureis to AsterixDB.
10. k.txt: a sample file of  'KofQueries' and used by 'getExeTime'. 
There are six fields: original data table, keyword, k1, sample data table,k0, quality. The first function output this file, and the second
function take it as input to evaluate the execution time of each query.