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Up to 11 GB RAM is used by following SQL Statements, how can I optimize RAM usage?

Those are the SQL tables I am taking the data from
String sql = "CREATE TABLE IF NOT EXISTS term_index (\n"
+ " term_id integer PRIMARY KEY AUTOINCREMENT ,\n"
+ " term text ,\n"
+ " multiterm integer \n"
+ ");";
execute(sql);
sql = "CREATE TABLE IF NOT EXISTS doc_term (\n"
+ " term_id integer ,\n"
+ " wiki_id text ,\n"
+ " section text ,\n"
+ " freq integer ,\n"
+ " tfidf double ,\n"
+ " cvalue double ,\n"
+ " rake double ,\n"
+ " PRIMARY KEY (term_id, wiki_id, section) \n"
+ ");";
execute(sql);
This is the SQL statement to take the termIDs from the tables above
/**
*
* #param wikiID
* #return
*/
public HashSet<Integer> getWholeDocumentTermIDs(String wikiID) {
HashSet<Integer> termIDs = new HashSet<Integer>();
String sql= "SELECT term_id FROM doc_term WHERE wiki_id = ?";
try {
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setString(1,wikiID);
ResultSet rs = stmt.executeQuery();
while (rs.next()) {
String sql2= "SELECT term_id, multiterm FROM term_index WHERE term_id = ?";
PreparedStatement stmt2 = conn.prepareStatement(sql2);
//System.out.println(rs.getInt("term_id"));
int term_id = rs.getInt("term_id");
if(term_id != 0) {
stmt2.setInt(1,term_id);
ResultSet rs2 = stmt2.executeQuery();
int multiterm = rs2.getInt("multiterm");
if(multiterm == 0) {
termIDs.add(term_id);
}
rs2.close();
}
}
rs.close();
} catch (SQLException e) {
System.out.println(e.getMessage() + "in getWholeDocumentTermIDs");
}
return termIDs;
}
The function getWholeDocumentTermIDs(String wikiID) is called 30 k times, meaning for 30 k wikiIDS, so when executing this, steadily more and more RAM is used by my IDE, starting at roughly 1,3 GB to later up to 10 or 11 GB, at which point the process starts to slown heavily. My question is if and how I can reduce/clean up the RAM to fetch all the required data stored in those tables.

no such column: hey (code 1 SQLITE_ERROR[1]): , while compiling: SELECT ID FROM ALLWORKHOURS WHERE NOTEMEMOS = hey

Log Cat:
no such column: hey (code 1 SQLITE_ERROR[1]): , while compiling: SELECT ID FROM ALLWORKHOURS WHERE NOTEMEMOS = hey
code:
102) public String getID(String note){
103) SQLiteDatabase db = this.getWritableDatabase();
104) String query = ("SELECT " + COL_0 + " FROM " + TABLE_NAME + " WHERE " + COL_5 + " = " + note);
105) db.rawQuery(query,null);
106) return query;
107) }
I do have a column name hey in my Database
Database Picture

Your terminology is confused.
hey is a value, NOTEMEMOS is a column.
You need to quote the value hey to let the SQL compiler know that it is a string value, rather than a column you are trying to compare against.
String query = ("SELECT " + COL_0 + " FROM " + TABLE_NAME + " WHERE " + COL_5 + " = '" + note + "'");
Just a note, you would be better off using a parameterised query, as using raw values is insecure (see SQL injection).
String query = ("SELECT " + COL_0 + " FROM " + TABLE_NAME + " WHERE " + COL_5 + " = ?"); // That's right, quotes aren't needed for a parameterized query.
String result = "";
Cursor cursor = db.rawQuery(query,new String[] {note} );
if (cursor.moveToFirst()) {
result = cursor.getString(cursor.getColumnIndex(COL_0));
}
cursor.close();
return result;

Your query should look like this
SELECT ID FROM ALLWORKHOURS WHERE NOTEMEMOS = 'hey'
Let me know if it helps

The way that you concatenate the parameter note creates this sql statement:
SELECT ID FROM ALLWORKHOURS WHERE NOTEMEMOS = hey
so hey is considered a column identifier and not a string literal because it is not enclosed inside single quotes.
You could do this instead:
String query = "SELECT " + COL_0 + " FROM " + TABLE_NAME + " WHERE " + COL_5 + " = '" + note + "'";
and it would work.
But the recommended way is passing parameters as a string array like this:
String query = "SELECT " + COL_0 + " FROM " + TABLE_NAME + " WHERE " + COL_5 + " = ?";
Cursor cursor = db.rawQuery(query, new String[] {note});
return cursor;
This way you don't worry about single quotes as this is taken care of by rawQuery().
I guess you want to return the Cursor object and not the sql query string, right?

jdbc application update sql isnt working for me, any ideas

public void Update(String name, String mobile, String email, String car, String model, String year, String color, String plate_no, String plateletters,String gear, String km, String date,String licesnse,String status, String notes){
Connection conn = null;
try{
conn = DriverManager.getConnection(CONN_STRING, USERNAME, PASSWORD);
System.out.println("connected");
Statement stmt = (Statement) conn.createStatement();
String ins = "update car"
+ "set Name = '"+name+"' , "
+ "Email = '"+email+"' , "
+ "Car = '"+car+"' , "
+ "Model = '"+model+"' , "
+ "Year = '"+year+"' , "
+ "Color = '"+color+"' , "
+ "Plateno = '"+plate_no+"' , "
+ "Plateletters = '"+plateletters+"' , "
+ "Gearbox = '"+gear+"' , "
+ "Km = '"+km+"' , "
+ "Date = '"+date+"' , "
+ "License = '"+licesnse+"' , "
+ "Status = '"+status+"' , "
+ "Notes = '"+notes+"' "
+ "where Mobile = '"+mobile+"' ";
stmt.execute(ins);
}catch(SQLException e){
JOptionPane.showMessageDialog(null, e.getMessage());
System.err.println(e);
return;
}
}
**i have tried prepared statment and stmt.executeUpdate(ins); but nothing workes !!
Please help!**
the error :
java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= 'ahmed' , Email = 'ahmed#hotmail.com' , Car = 'honda' , Model = 'hondaz' , Yea' at line 1

You need to make sure you add proper space between elements in your SQL query:
String ins = "update car"
should be
String ins = "update car "
A good approach to doing this is to write and execute your SQL in your database query tool (SQL developer, phpMyAdmin, whatever) and make sure your syntax is good before trying to re-write it in Java.

Use a preparedStatement instaed of a Statement.
Connection conn = null;
try{
conn = DriverManager.getConnection(CONN_STRING, USERNAME, PASSWORD);
PreparedStatement pstm = conn.prepareStatement(
"update car "
+ "set Name = ? ,"
+ "Email = ? ,"
+ "Car = ? ,"
+ "Model = ? ,"
+ "Year = ? ,"
+ "Color = ? ,"
+ "Plateno = ? ,"
+ "Plateletters = ? ,"
+ "Gearbox = ? ,"
+ "Km = ?,"
+ "Date = ?,"
+ "License = ?, "
+ "Status = ?, "
+ "Notes = ? "
+ "where mobile = ?"
);
pstm.setObject(1, name);
pstm.setObject(2, email);
pstm.setObject(3, car);
pstm.setObject(4, model);
pstm.setObject(5, year);
pstm.setObject(6, color);
pstm.setObject(7, plate_no);
pstm.setObject(8, plateletters);
pstm.setObject(9, gear);
pstm.setObject(10, km);
pstm.setObject(11, date);
pstm.setObject(12, licesnse);
pstm.setObject(13, status);
pstm.setObject(14, notes);
pstm.setObject(15, mobile);
pstm.executeUpdate();
}catch(SQLException e){
e.printStackTrace();
}

SQLite java.lang.NullPointerException in only select query

i added sqlite-jdbc-3.7.2.jar to build path. I used insert query. when i opened the wellec.db with notepad, i can see records. But my select is not working.
HERE WellInfo class properties
public Integer wellID;
public Integer measurement;
public String wellname;
public Integer wellstatus;
public String licenseno;
public String gl;
public String kb;
public String spuddate;
public String drillingenddate;
public String totaldepth;
public String notes;
public String easting;
public String northing;
public String coordinatesystem;
public Integer islogadd;
here is my createtable sql
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:wellec.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "CREATE TABLE IF NOT EXISTS WELLINFO " +
"(ID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL ," +
" WELLNAME CHAR(90) NOT NULL, " +
" WELLSTATUS INT NOT NULL," +
" MEASUREMENT INT NOT NULL," +
" ISLOGADD INT NOT NULL," +
" GL CHAR(50) NOT NULL, " +
" KB CHAR(50) NOT NULL, " +
" SPUDDATE CHAR(50) NOT NULL, " +
" TOTALDEPTH CHAR(50) NOT NULL, " +
" LICENSENO CHAR(50) NOT NULL, " +
" DRILLINGENDDATE CHAR(50) NOT NULL, " +
" NOTES CHAR(150) NOT NULL, " +
" EASTING CHAR(50) NOT NULL, " +
" NORTHING CHAR(50) NOT NULL, " +
" COORDINATESYSTEM CHAR(50) NOT NULL)";
stmt.executeUpdate(sql);
...//other tables sql and stmt.executeUpdate(sql)
stmt.close();
c.commit();
here is my insert query which is working. WellInfo wi as parameter
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:wellec.db");
c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
String sql = "INSERT INTO WELLINFO " +
"(ID, WELLNAME, WELLSTATUS , MEASUREMENT, ISLOGADD , GL, KB, SPUDDATE, TOTALDEPTH, " +
"LICENSENO , DRILLINGENDDATE, NOTES, EASTING, NORTHING, COORDINATESYSTEM) " +
"VALUES (NULL,'" + wi.wellname + "'," + wi.wellstatus + "," + wi.measurement + "," +
"" + wi.islogadd +",'" + wi.gl + "','" + wi.kb + "','" + wi.spuddate + "'," +
"'" + wi.totaldepth + "','" + wi.licenseno + "','" + wi.drillingenddate + "', " +
"'" + wi.notes + "','" + wi.easting + "','" + wi.northing + "','" + wi.coordinatesystem + "');";
stmt.executeUpdate(sql);
stmt.close();
c.commit();
} catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Records created successfully");
return 0;
here is my select
Connection c = null;
Statement stmt = null;
WellInfo[] wi = new WellInfo[60000];
WellInfo[] wi2 = new WellInfo[0];
int i = 0;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:wellec.db");
//c.setAutoCommit(false);
System.out.println("Opened database successfully");
stmt = c.createStatement();
ResultSet rs = stmt.executeQuery("select * from WELLINFO");
//c.commit();
//if(rs.getRow() > 0)
while ( rs.next() ) { //HERE IS THE PROBLEM
wi[i].wellID = rs.getInt("ID");
i++;
}
wi2 = new WellInfo[i];
for(int j = 0; j < i - 1; j++){
wi2[j] = wi[j];
}
rs.close();
stmt.close();
return wi2;
} catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
System.out.println("Operation done successfully");
return wi2;
Sorry not specify the problem. Here it is:
SELECT QUERY problem when i call rs.next(), i got the error java.lang.NullPointerException.

wi[i] is null => you can't call wi[i].wellID before you instantiate wi[i], you should do something like
wi[i] = new WellInfo() then call wi[i].wellID

SQL logic error or missing database in Blackberry programming

I am trying to insert data into a SQLite database from a blackberry. When I call the screen I also call a method to create the database:
boolean sdCardPresent = false;
public static Database sqliteDB;
URI uri;
public void createdatabase()
{
try{
Enumeration e = FileSystemRegistry.listRoots();
root = (String)e.nextElement();
Dialog.inform(root);
if(root.equalsIgnoreCase("sdcard/"))
{
sdCardPresent = true;
}
if(!sdCardPresent)
{
Dialog.inform("O seu dispositivo nao suporta este compartimento sem cartao de memoria, verifique se existe um SD card no seu dispositivo.");
UiApplication.getUiApplication().pushScreen(new Tab_Main());
}else{
uri = URI.create(
"file:///SDCard/Databases/MBA.db");
sqliteDB = DatabaseFactory.openOrCreate(uri);
sqliteDB = DatabaseFactory.open(uri);
Statement st = sqliteDB.createStatement("DROP TABLE IF EXISTS atms;CREATE TABLE atms " +
"( id INTEGER PRIMARY KEY AUTOINCREMENT ," +
" localizacao TEXT, " +
" mapa TEXT ," +
" foto1 TEXT ," +
" foto2 TEXT," +
" zona TEXT);" +
"" +
"DROP TABLE IF EXISTS balcoes;CREATE TABLE balcoes " +
"( id INTEGER PRIMARY KEY AUTOINCREMENT ," +
" localizacao TEXT, " +
" mapa TEXT ," +
" foto1 TEXT ," +
" foto2 TEXT," +
" zona TEXT);" +
"" +
"DROP TABLE IF EXISTS contactos;CREATE TABLE contactos " +
"( id INTEGER PRIMARY KEY AUTOINCREMENT ," +
" nome TEXT, " +
" numero_conta INTEGER);") ;
st.prepare();
st.execute();
st.close();
sqliteDB.close();
Dialog.inform("Status: Database was successfully created.");
//}
} catch (Exception e){
System.out.println(e.getMessage());
Dialog.inform("\n "+e);
//UiApplication.getUiApplication().popScreen(Screen);
}
}
After that I use some Editfields and other components to get the values. I call the method to insert the parameters and send the query:
public void insert_update(String query) {
try {
sqliteDB = DatabaseFactory.openOrCreate(uri);
Statement st = sqliteDB.createStatement(query);
//Statement statement = _db.createStatement(query);
st.prepare();
st.execute();
st.close();
Dialog.inform("Adicionado com sucesso!!!");
}
catch ( Exception e ) {
Dialog.inform(e+"");
}
}
For example when I call it with the query = "insert into contactos values (null,"a","1"); I get an exception. SQL logic error or missing database.

Try dropping the quotes around the third column value.
INSERT INTO contactos VALUES (null,"a", 1);
It's defined as an INTEGER.
numero_conta INTEGER
EDIT :
System.out.println(uri); // check if null, or different
if (uri == null) {
uri = URI.create(
"file:///SDCard/Databases/MBA.db");
}
sqliteDB = DatabaseFactory.openOrCreate(uri);
sqliteDB = DatabaseFactory.open(uri); // open again
Statement st = sqliteDB.createStatement(query);