trunk/tools/ClusterConnection.java

package tools;
import java.sql.*;

/**
 * ClusterConnection class to wrap the master/node mysql servers so that is transparent to other programs
 * @author Jose Duarte
 */
//TODO Maybe we should always pass the key for CreateStatement and the constructor and drop the 2 methods without key.
//TODO I think that should make things easier. To have to remember to be switching keys is not ideal, I'd rather pass it always as a parameter in CreateStatement
//TODO The only problem with this approach is when constructing the object the key must be passed. That shouldn't be a major problem anyway. Revise all this

public class ClusterConnection {

        private final String url= "jdbc:mysql://";
        private final String masterDb="key_master"; 
        private final String masterHost="white";
        private Connection nCon;
        private Connection mCon;
        public String keyTable;
        public String key;
        public String idxColumn;
        public String host;
        public String db;
        private String user;
        private String password;
        
        //create a ClusterConnection passing a key. Then we need to call createNConStatement only passing the idx as argument.
        public ClusterConnection (String db,String key, String user,String password) {
                new ClusterConnection(db,user,password);
                this.key=key; //can't use the setKey method here before we've got the db field initialized
                setIdxColumn();
                setMasterTable(db);
        }

        // create a cluster connection with an empty key field. In this case we need to call createNConStatement passing the key as argument 
        public ClusterConnection (String db, String user,String password) { 
                loadMySQLDriver();
                setDb(db);
                setUser(user);
                setPassword(password);
                try {
                        // For nCon we create a connection to the master too. 
                        // This is just a place holder because the actual node connection is not created until we create the statement
                        // If we don't do this then when closing the two connections an exception might occurr because we try to close a non existing object
                        this.nCon = DriverManager.getConnection(url+masterHost+"/"+masterDb,user,password);
                        this.mCon = DriverManager.getConnection(url+masterHost+"/"+masterDb,user,password);
                }
                catch(SQLException e){
            System.out.println("SQLException: " + e.getMessage());
            System.out.println("SQLState:     " + e.getSQLState());
            System.out.println("VendorError:  " + e.getErrorCode());
                        System.out.println("Couldn't get connection to master host "+masterHost+", db="+masterDb+", exiting.");
                        System.exit(2);                 
                }
        }

        
        public void loadMySQLDriver() {
                try {
                        Class.forName("com.mysql.jdbc.Driver");
                }
                catch(Exception e) {
                        System.out.println(e.getMessage());
                        System.out.println("An exception occurred while loading the mysql jdbc driver, exiting.");
                        System.exit(1);
                }
        }
        public void close() {
                try {
                        this.nCon.close();
                        this.mCon.close();
                }
                catch(SQLException e) {
                        System.out.println("Couldn't close database connections for master: "+masterHost+" and node: "+this.host+", exiting.");
            System.out.println("SQLException: " + e.getMessage());
            System.out.println("SQLState:     " + e.getSQLState());
                        System.exit(3);                                         
                }
        }
        
        public String getHost4Idx (int idx) {
                String host="";
                Statement S;
                ResultSet R;
                try {
                        S=mCon.createStatement();
                        String query="SELECT client_name FROM "+keyTable+" AS m INNER JOIN clients_names AS c "+
                                                "ON (m.client_id=c.client_id) WHERE "+idxColumn+"="+idx+";";
                        R=S.executeQuery(query);
                        if (R.next()){
                                host=R.getString(1);
                        }
                        S.close();
                        R.close();
                }
                catch(SQLException e) {
                        System.out.println("Couldn't get the host name for idx "+idx+", exiting");
            System.out.println("SQLException: " + e.getMessage());
            System.out.println("SQLState:     " + e.getSQLState());
                        System.exit(3);                                                                 
                }
                return host;
        }
        
        public void setHostFromIdx(int idx){
                setHost(getHost4Idx(idx));
        }
        
        public void setHost(String host) {
                this.host=host;
                try {
                        //Closing previous connection is essential
                        //If we don't close it a lot of connections stay open after using a ClusterConnection object for a while
                        this.nCon.close(); 
                        this.nCon=DriverManager.getConnection(url+host+"/"+db,user,password);
                }
                catch (SQLException e){
            System.out.println("SQLException: " + e.getMessage());
            System.out.println("SQLState:     " + e.getSQLState());
                        System.out.println("Couldn't get connection to node "+host+", exiting.");
                        System.exit(2);                                         
                }
        }
        
        public Statement createStatement(int idx) { // to use when the field "key" is already set
                setMasterTable();
                setIdxColumn();
                Statement S=null;
                this.setHostFromIdx(idx);
                try {
                        S=this.nCon.createStatement();
                }
                catch (SQLException e){
                        System.out.println("SQLException: " + e.getMessage());
                        System.out.println("SQLState:     " + e.getSQLState());
                        System.out.println("Couldn't create statement for the node connection, idx= "+idx+", exiting.");
                        System.exit(2);                                                                 
                }
                return S;
        }
        
        public Statement createStatement(String key,int idx) {
                setKey(key);
                return createStatement(idx);
        }
        
        public void setMasterTable(String db) { // to set masterTable field in constructor (i.e. first time)
                this.keyTable=db+"_"+this.key+"_list_master";
        }
        
        public void setMasterTable() { // to set masterTable field when db is already set 
                this.keyTable=this.db+"_"+this.key+"_list_master";
        }
        
        public String getMasterTable() {
                return this.keyTable;
        }
        
        public void setIdxColumn() {
                this.idxColumn=this.key+"_id";
        }

        public void setUser(String user) {
                this.user=user;
        }

        public void setPassword(String password) {
                this.password=password;
        }
        
        public void setDb(String db){
                this.db=db;
        }
        
        public void setKey(String key){
                this.key=key;
                setMasterTable();
                setIdxColumn();
        }

        public Statement createMasterStatement() { 
                Statement S=null;
                try {
                        S=this.mCon.createStatement();
                }
                catch (SQLException e){
                        System.out.println("SQLException: " + e.getMessage());
                        System.out.println("SQLState:     " + e.getSQLState());
                        System.out.println("Couldn't create statement for the master connection, exiting.");
                        System.exit(2);                                                                 
                }
                return S;
        }

        public ResultSet getAllIdxFromMaster(String key) { 
                this.setKey(key);
                String query;
                Statement S;
                ResultSet R=null;
                try {
                        query="SELECT "+idxColumn+" FROM "+keyTable+";";
                        S=this.mCon.createStatement();
                        R=S.executeQuery(query);
                        //S.close(); // apparently it doesn't work if we close the Statement!! Don't know why!
                }
                catch (SQLException e){
                        System.out.println("SQLException: " + e.getMessage());
                        System.out.println("SQLState:     " + e.getSQLState());
                        System.out.println("Couldn't get all indices from columnn "+idxColumn+" in table "+keyTable+" from "+masterDb+" database in "+masterHost+", exiting.");
                        System.exit(2);                                                                 
                }
                return R;
        }

        //       to get client_id for a certain idx and key
        //TODO will need to change the query. In general this method would return more than 1 client_id if the idx is not unique
        public int getHostId4Idx (String key,int idx) { 
                int hostId=0;
                this.setKey(key);
                Statement S;
                ResultSet R;
                String query;
                int countCids=0;
                try {
                        S=mCon.createStatement();
                        query="SELECT count(client_id) FROM "+keyTable+" WHERE "+idxColumn+"="+idx+";";
                        R=S.executeQuery(query);
                        if (R.next()){
                                countCids=R.getInt(1);
                        }
                        if (countCids!=1){
                                System.out.println("Error! the number of client_id for idx "+idxColumn+"= "+idx+" is bigger than 1. Check what's wrong! Exiting now.");
                                System.exit(2);
                        }
                        else {
                                query="SELECT client_id FROM "+keyTable+" WHERE "+idxColumn+"="+idx+";";
                                R=S.executeQuery(query);
                                if (R.next()){
                                        hostId=R.getInt(1);
                                }
                        }
                        S.close();
                        R.close();
                }
                catch(SQLException e) {
                        System.out.println("Couldn't get the host id for idx "+idxColumn+"="+idx+", exiting");
            System.out.println("SQLException: " + e.getMessage());
            System.out.println("SQLState:     " + e.getSQLState());
                        System.exit(3);                                                                 
                }
                return hostId;
        }
        
        public void insertIdxInMaster(String key, int clientId) {
                Statement S;
                String query;
                this.setKey(key);
                try {
                        S=this.mCon.createStatement();
                        query="INSERT INTO "+this.keyTable+" (client_id) VALUES ("+clientId+");";
                        S.executeUpdate(query);
                        S.close();
                } 
                catch (SQLException E) {
                        System.out.println("SQLException: " + E.getMessage());
                        System.out.println("SQLState:     " + E.getSQLState());
                        System.out.println("Couldn't insert new "+this.idxColumn+" in master table "+this.getMasterTable()+". The client_id for it was "+clientId+". Exiting.");
                        System.exit(2);
                } 
        }

        public void insertIdxInMaster(String keySrc,String keyDest,int idxSrc) {
                this.setKey(keySrc);
                int clientId=0;
                clientId=this.getHostId4Idx(keySrc,idxSrc);
                insertIdxInMaster(keyDest,clientId);
        }

        public int getLastInsertId(String key) {
                int lastIdx=0;
                this.setKey(key);
                Statement S;
                ResultSet R;
                String query = "";
                try {
                        S = this.mCon.createStatement();
                        query = "SELECT LAST_INSERT_ID() FROM "+this.keyTable+" LIMIT 1;";
                        R = S.executeQuery(query);
                        if (R.next()) {
                                lastIdx=R.getInt(1);
                        }
                        R.close();
                        S.close();
                } 
                catch (SQLException E) {
                        System.out.println("Couldn't get the last insert id for key type "+this.idxColumn+" from table "+this.keyTable+". Exiting");
                        System.out.println("SQLException: " + E.getMessage());
                        System.out.println("SQLState:     " + E.getSQLState());
                        System.exit(3);
                } // end try/catch connection 
                return lastIdx;
        } // end getGraphId
        
        public int[][] getIdxSet(String key) { 
                int[][] indMatrix=null;
                this.setKey(key);
                String query;
                Statement S;
                ResultSet R;
                try {
                        // STEP 1 -- getting set of all client_ids
                        S=this.mCon.createStatement();
                        query="SELECT count(distinct client_id) FROM "+keyTable+";";
                        int count=0;
                        R=S.executeQuery(query);
                        if (R.next()){
                                count=R.getInt(1);
                        }
                        query="SELECT DISTINCT client_id FROM "+keyTable+" ORDER BY client_id;";
                        //R.close();
                        //S.close();
                        R=S.executeQuery(query);
                        
                        // STEP 2 -- putting sets of indices counts into temp tables c_<client_id> with a serial auto_increment field
                        int[] clids=new int[count]; //array to store all client_ids. To be used in loops later
                        int i=0;
                        while (R.next()){
                                Statement Sloop=this.mCon.createStatement();
                                int clid=R.getInt(1);
                                query="CREATE TEMPORARY TABLE c_"+clid+" (serial int(11) NOT NULL AUTO_INCREMENT,"+idxColumn+" int(11),client_id int(11), PRIMARY KEY(serial));";                               
                                Sloop.executeUpdate(query);
                                query="INSERT INTO c_"+clid+" ("+idxColumn+",client_id) SELECT "+idxColumn+",client_id FROM "+keyTable+" WHERE client_id="+clid+";";
                                Sloop.executeUpdate(query);
                                clids[i]=clid;
                                i++;
                                Sloop.close();
                        }
                        
                        // STEP3 -- merging all c_<client_id> tables into a temp table tmp_allcs and selecting the client_id with the maximum count
                        //query="SELECT client_id,count(*) as c FROM c_34 GROUP BY client_id UNION SELECT client_id,count(*) as c FROM c_32 GROUP BY client_id;";
                        query="DROP TABLE IF EXISTS tmp_allcs;"; 
                        S.executeUpdate(query);
                        //this table must be permanent! otherwise cannot do the select max(c) later
                        query="CREATE TABLE IF NOT EXISTS tmp_allcs (client_id int(11), c int(11)) ENGINE=MEMORY;";
                        S.executeUpdate(query);
                        String unionStr="SELECT client_id,count(*) AS c FROM c_"+clids[0]+" GROUP BY client_id";
                        for (i=1;i<clids.length;i++) {
                                unionStr+=" UNION SELECT client_id,count(*) AS c FROM c_"+clids[i]+" GROUP BY client_id";
                        }
                        query="INSERT INTO tmp_allcs "+unionStr+";";
                        S.executeUpdate(query);
                        query="SELECT client_id,c FROM tmp_allcs WHERE c=(SELECT max(c) FROM tmp_allcs);";
                        R=S.executeQuery(query);
                        int clidMaxIdxCount=0;
                        int maxIdxCount=0;
                        if (R.next()) {
                                clidMaxIdxCount=R.getInt(1);
                                maxIdxCount=R.getInt(2);
                        }
                        query="DROP TABLE tmp_allcs;";
                        S.executeUpdate(query);
                        
                        // STEP 4 -- join all c_<client_id> tables into a table with a serial column, and c_<client_id> columns each of them with the indices for each client_id 
                        //query="SELECT c_34.serial,c_34.asu_id AS c_34,c_32.asu_id AS c_32,c_36.asu_id AS c_36 FROM c_34 LEFT JOIN c_32 ON (c_34.serial=c_32.serial) LEFT JOIN c_36 ON (c_34.serial=c_36.serial);";
                        String selectStr="c_"+clidMaxIdxCount+".serial, c_"+clidMaxIdxCount+"."+idxColumn+" AS c_"+clidMaxIdxCount;
                        String fromStr="c_"+clidMaxIdxCount;
                        for (i=0;i<clids.length;i++) {
                                if (clids[i]!=clidMaxIdxCount){
                                        selectStr+=", c_"+clids[i]+"."+idxColumn+" AS c_"+clids[i];
                                        fromStr+=" LEFT JOIN c_"+clids[i]+" ON (c_"+clidMaxIdxCount+".serial=c_"+clids[i]+".serial)";
                                }
                        } 
                        query="CREATE TEMPORARY TABLE indices_matrix "+"SELECT "+selectStr+" FROM "+fromStr+";";
                        S.executeUpdate(query);
                        
                        // STEP 5 -- put the table into a 2-dimensional array and return it
                        indMatrix = new int[maxIdxCount][clids.length];
                        query="SELECT * FROM indices_matrix";
                        R=S.executeQuery(query);
                        i=0;
                        while (R.next()) {
                                for (int j=0;j<clids.length;j++){
                                        indMatrix[i][j]=R.getInt(j+2);
                                }
                                i++;
                        }
                        R.close();
                        S.close();
                }
                catch (SQLException e){
                        System.out.println("SQLException: " + e.getMessage());
                        System.out.println("SQLState:     " + e.getSQLState());
                        System.out.println("Couldn't get the indices set from columnn "+idxColumn+" in table "+keyTable+" from "+masterDb+" database in "+masterHost+", exiting.");
                        System.exit(2);                                                                 
                }
                return indMatrix;
        }

        
}
Revision:	23
Committed:	Wed Mar 8 15:25:45 2006 UTC (18 years, 6 months ago) by duarte
File size:	13600 byte(s)
Log Message:	Fixed important bug: - now closing nCon connection before opening a new one in the setHost method. - this is important. Before lots of connection were left opened after having used the ClusterConnection object
Line	File contents
1	package tools;
2	import java.sql.*;
3
4	/**
5	* ClusterConnection class to wrap the master/node mysql servers so that is transparent to other programs
6	* @author Jose Duarte
7	*/
8	//TODO Maybe we should always pass the key for CreateStatement and the constructor and drop the 2 methods without key.
9	//TODO I think that should make things easier. To have to remember to be switching keys is not ideal, I'd rather pass it always as a parameter in CreateStatement
10	//TODO The only problem with this approach is when constructing the object the key must be passed. That shouldn't be a major problem anyway. Revise all this
11
12	public class ClusterConnection {
13
14	private final String url= "jdbc:mysql://";
15	private final String masterDb="key_master";
16	private final String masterHost="white";
17	private Connection nCon;
18	private Connection mCon;
19	public String keyTable;
20	public String key;
21	public String idxColumn;
22	public String host;
23	public String db;
24	private String user;
25	private String password;
26
27	//create a ClusterConnection passing a key. Then we need to call createNConStatement only passing the idx as argument.
28	public ClusterConnection (String db,String key, String user,String password) {
29	new ClusterConnection(db,user,password);
30	this.key=key; //can't use the setKey method here before we've got the db field initialized
31	setIdxColumn();
32	setMasterTable(db);
33	}
34
35	// create a cluster connection with an empty key field. In this case we need to call createNConStatement passing the key as argument
36	public ClusterConnection (String db, String user,String password) {
37	loadMySQLDriver();
38	setDb(db);
39	setUser(user);
40	setPassword(password);
41	try {
42	// For nCon we create a connection to the master too.
43	// This is just a place holder because the actual node connection is not created until we create the statement
44	// If we don't do this then when closing the two connections an exception might occurr because we try to close a non existing object
45	this.nCon = DriverManager.getConnection(url+masterHost+"/"+masterDb,user,password);
46	this.mCon = DriverManager.getConnection(url+masterHost+"/"+masterDb,user,password);
47	}
48	catch(SQLException e){
49	System.out.println("SQLException: " + e.getMessage());
50	System.out.println("SQLState: " + e.getSQLState());
51	System.out.println("VendorError: " + e.getErrorCode());
52	System.out.println("Couldn't get connection to master host "+masterHost+", db="+masterDb+", exiting.");
53	System.exit(2);
54	}
55	}
56
57
58	public void loadMySQLDriver() {
59	try {
60	Class.forName("com.mysql.jdbc.Driver");
61	}
62	catch(Exception e) {
63	System.out.println(e.getMessage());
64	System.out.println("An exception occurred while loading the mysql jdbc driver, exiting.");
65	System.exit(1);
66	}
67	}
68	public void close() {
69	try {
70	this.nCon.close();
71	this.mCon.close();
72	}
73	catch(SQLException e) {
74	System.out.println("Couldn't close database connections for master: "+masterHost+" and node: "+this.host+", exiting.");
75	System.out.println("SQLException: " + e.getMessage());
76	System.out.println("SQLState: " + e.getSQLState());
77	System.exit(3);
78	}
79	}
80
81	public String getHost4Idx (int idx) {
82	String host="";
83	Statement S;
84	ResultSet R;
85	try {
86	S=mCon.createStatement();
87	String query="SELECT client_name FROM "+keyTable+" AS m INNER JOIN clients_names AS c "+
88	"ON (m.client_id=c.client_id) WHERE "+idxColumn+"="+idx+";";
89	R=S.executeQuery(query);
90	if (R.next()){
91	host=R.getString(1);
92	}
93	S.close();
94	R.close();
95	}
96	catch(SQLException e) {
97	System.out.println("Couldn't get the host name for idx "+idx+", exiting");
98	System.out.println("SQLException: " + e.getMessage());
99	System.out.println("SQLState: " + e.getSQLState());
100	System.exit(3);
101	}
102	return host;
103	}
104
105	public void setHostFromIdx(int idx){
106	setHost(getHost4Idx(idx));
107	}
108
109	public void setHost(String host) {
110	this.host=host;
111	try {
112	//Closing previous connection is essential
113	//If we don't close it a lot of connections stay open after using a ClusterConnection object for a while
114	this.nCon.close();
115	this.nCon=DriverManager.getConnection(url+host+"/"+db,user,password);
116	}
117	catch (SQLException e){
118	System.out.println("SQLException: " + e.getMessage());
119	System.out.println("SQLState: " + e.getSQLState());
120	System.out.println("Couldn't get connection to node "+host+", exiting.");
121	System.exit(2);
122	}
123	}
124
125	public Statement createStatement(int idx) { // to use when the field "key" is already set
126	setMasterTable();
127	setIdxColumn();
128	Statement S=null;
129	this.setHostFromIdx(idx);
130	try {
131	S=this.nCon.createStatement();
132	}
133	catch (SQLException e){
134	System.out.println("SQLException: " + e.getMessage());
135	System.out.println("SQLState: " + e.getSQLState());
136	System.out.println("Couldn't create statement for the node connection, idx= "+idx+", exiting.");
137	System.exit(2);
138	}
139	return S;
140	}
141
142	public Statement createStatement(String key,int idx) {
143	setKey(key);
144	return createStatement(idx);
145	}
146
147	public void setMasterTable(String db) { // to set masterTable field in constructor (i.e. first time)
148	this.keyTable=db+"_"+this.key+"_list_master";
149	}
150
151	public void setMasterTable() { // to set masterTable field when db is already set
152	this.keyTable=this.db+"_"+this.key+"_list_master";
153	}
154
155	public String getMasterTable() {
156	return this.keyTable;
157	}
158
159	public void setIdxColumn() {
160	this.idxColumn=this.key+"_id";
161	}
162
163	public void setUser(String user) {
164	this.user=user;
165	}
166
167	public void setPassword(String password) {
168	this.password=password;
169	}
170
171	public void setDb(String db){
172	this.db=db;
173	}
174
175	public void setKey(String key){
176	this.key=key;
177	setMasterTable();
178	setIdxColumn();
179	}
180
181	public Statement createMasterStatement() {
182	Statement S=null;
183	try {
184	S=this.mCon.createStatement();
185	}
186	catch (SQLException e){
187	System.out.println("SQLException: " + e.getMessage());
188	System.out.println("SQLState: " + e.getSQLState());
189	System.out.println("Couldn't create statement for the master connection, exiting.");
190	System.exit(2);
191	}
192	return S;
193	}
194
195	public ResultSet getAllIdxFromMaster(String key) {
196	this.setKey(key);
197	String query;
198	Statement S;
199	ResultSet R=null;
200	try {
201	query="SELECT "+idxColumn+" FROM "+keyTable+";";
202	S=this.mCon.createStatement();
203	R=S.executeQuery(query);
204	//S.close(); // apparently it doesn't work if we close the Statement!! Don't know why!
205	}
206	catch (SQLException e){
207	System.out.println("SQLException: " + e.getMessage());
208	System.out.println("SQLState: " + e.getSQLState());
209	System.out.println("Couldn't get all indices from columnn "+idxColumn+" in table "+keyTable+" from "+masterDb+" database in "+masterHost+", exiting.");
210	System.exit(2);
211	}
212	return R;
213	}
214
215	// to get client_id for a certain idx and key
216	//TODO will need to change the query. In general this method would return more than 1 client_id if the idx is not unique
217	public int getHostId4Idx (String key,int idx) {
218	int hostId=0;
219	this.setKey(key);
220	Statement S;
221	ResultSet R;
222	String query;
223	int countCids=0;
224	try {
225	S=mCon.createStatement();
226	query="SELECT count(client_id) FROM "+keyTable+" WHERE "+idxColumn+"="+idx+";";
227	R=S.executeQuery(query);
228	if (R.next()){
229	countCids=R.getInt(1);
230	}
231	if (countCids!=1){
232	System.out.println("Error! the number of client_id for idx "+idxColumn+"= "+idx+" is bigger than 1. Check what's wrong! Exiting now.");
233	System.exit(2);
234	}
235	else {
236	query="SELECT client_id FROM "+keyTable+" WHERE "+idxColumn+"="+idx+";";
237	R=S.executeQuery(query);
238	if (R.next()){
239	hostId=R.getInt(1);
240	}
241	}
242	S.close();
243	R.close();
244	}
245	catch(SQLException e) {
246	System.out.println("Couldn't get the host id for idx "+idxColumn+"="+idx+", exiting");
247	System.out.println("SQLException: " + e.getMessage());
248	System.out.println("SQLState: " + e.getSQLState());
249	System.exit(3);
250	}
251	return hostId;
252	}
253
254	public void insertIdxInMaster(String key, int clientId) {
255	Statement S;
256	String query;
257	this.setKey(key);
258	try {
259	S=this.mCon.createStatement();
260	query="INSERT INTO "+this.keyTable+" (client_id) VALUES ("+clientId+");";
261	S.executeUpdate(query);
262	S.close();
263	}
264	catch (SQLException E) {
265	System.out.println("SQLException: " + E.getMessage());
266	System.out.println("SQLState: " + E.getSQLState());
267	System.out.println("Couldn't insert new "+this.idxColumn+" in master table "+this.getMasterTable()+". The client_id for it was "+clientId+". Exiting.");
268	System.exit(2);
269	}
270	}
271
272	public void insertIdxInMaster(String keySrc,String keyDest,int idxSrc) {
273	this.setKey(keySrc);
274	int clientId=0;
275	clientId=this.getHostId4Idx(keySrc,idxSrc);
276	insertIdxInMaster(keyDest,clientId);
277	}
278
279	public int getLastInsertId(String key) {
280	int lastIdx=0;
281	this.setKey(key);
282	Statement S;
283	ResultSet R;
284	String query = "";
285	try {
286	S = this.mCon.createStatement();
287	query = "SELECT LAST_INSERT_ID() FROM "+this.keyTable+" LIMIT 1;";
288	R = S.executeQuery(query);
289	if (R.next()) {
290	lastIdx=R.getInt(1);
291	}
292	R.close();
293	S.close();
294	}
295	catch (SQLException E) {
296	System.out.println("Couldn't get the last insert id for key type "+this.idxColumn+" from table "+this.keyTable+". Exiting");
297	System.out.println("SQLException: " + E.getMessage());
298	System.out.println("SQLState: " + E.getSQLState());
299	System.exit(3);
300	} // end try/catch connection
301	return lastIdx;
302	} // end getGraphId
303
304	public int[][] getIdxSet(String key) {
305	int[][] indMatrix=null;
306	this.setKey(key);
307	String query;
308	Statement S;
309	ResultSet R;
310	try {
311	// STEP 1 -- getting set of all client_ids
312	S=this.mCon.createStatement();
313	query="SELECT count(distinct client_id) FROM "+keyTable+";";
314	int count=0;
315	R=S.executeQuery(query);
316	if (R.next()){
317	count=R.getInt(1);
318	}
319	query="SELECT DISTINCT client_id FROM "+keyTable+" ORDER BY client_id;";
320	//R.close();
321	//S.close();
322	R=S.executeQuery(query);
323
324	// STEP 2 -- putting sets of indices counts into temp tables c_<client_id> with a serial auto_increment field
325	int[] clids=new int[count]; //array to store all client_ids. To be used in loops later
326	int i=0;
327	while (R.next()){
328	Statement Sloop=this.mCon.createStatement();
329	int clid=R.getInt(1);
330	query="CREATE TEMPORARY TABLE c_"+clid+" (serial int(11) NOT NULL AUTO_INCREMENT,"+idxColumn+" int(11),client_id int(11), PRIMARY KEY(serial));";
331	Sloop.executeUpdate(query);
332	query="INSERT INTO c_"+clid+" ("+idxColumn+",client_id) SELECT "+idxColumn+",client_id FROM "+keyTable+" WHERE client_id="+clid+";";
333	Sloop.executeUpdate(query);
334	clids[i]=clid;
335	i++;
336	Sloop.close();
337	}
338
339	// STEP3 -- merging all c_<client_id> tables into a temp table tmp_allcs and selecting the client_id with the maximum count
340	//query="SELECT client_id,count() as c FROM c_34 GROUP BY client_id UNION SELECT client_id,count() as c FROM c_32 GROUP BY client_id;";
341	query="DROP TABLE IF EXISTS tmp_allcs;";
342	S.executeUpdate(query);
343	//this table must be permanent! otherwise cannot do the select max(c) later
344	query="CREATE TABLE IF NOT EXISTS tmp_allcs (client_id int(11), c int(11)) ENGINE=MEMORY;";
345	S.executeUpdate(query);
346	String unionStr="SELECT client_id,count(*) AS c FROM c_"+clids[0]+" GROUP BY client_id";
347	for (i=1;i<clids.length;i++) {
348	unionStr+=" UNION SELECT client_id,count(*) AS c FROM c_"+clids[i]+" GROUP BY client_id";
349	}
350	query="INSERT INTO tmp_allcs "+unionStr+";";
351	S.executeUpdate(query);
352	query="SELECT client_id,c FROM tmp_allcs WHERE c=(SELECT max(c) FROM tmp_allcs);";
353	R=S.executeQuery(query);
354	int clidMaxIdxCount=0;
355	int maxIdxCount=0;
356	if (R.next()) {
357	clidMaxIdxCount=R.getInt(1);
358	maxIdxCount=R.getInt(2);
359	}
360	query="DROP TABLE tmp_allcs;";
361	S.executeUpdate(query);
362
363	// STEP 4 -- join all c_<client_id> tables into a table with a serial column, and c_<client_id> columns each of them with the indices for each client_id
364	//query="SELECT c_34.serial,c_34.asu_id AS c_34,c_32.asu_id AS c_32,c_36.asu_id AS c_36 FROM c_34 LEFT JOIN c_32 ON (c_34.serial=c_32.serial) LEFT JOIN c_36 ON (c_34.serial=c_36.serial);";
365	String selectStr="c_"+clidMaxIdxCount+".serial, c_"+clidMaxIdxCount+"."+idxColumn+" AS c_"+clidMaxIdxCount;
366	String fromStr="c_"+clidMaxIdxCount;
367	for (i=0;i<clids.length;i++) {
368	if (clids[i]!=clidMaxIdxCount){
369	selectStr+=", c_"+clids[i]+"."+idxColumn+" AS c_"+clids[i];
370	fromStr+=" LEFT JOIN c_"+clids[i]+" ON (c_"+clidMaxIdxCount+".serial=c_"+clids[i]+".serial)";
371	}
372	}
373	query="CREATE TEMPORARY TABLE indices_matrix "+"SELECT "+selectStr+" FROM "+fromStr+";";
374	S.executeUpdate(query);
375
376	// STEP 5 -- put the table into a 2-dimensional array and return it
377	indMatrix = new int[maxIdxCount][clids.length];
378	query="SELECT * FROM indices_matrix";
379	R=S.executeQuery(query);
380	i=0;
381	while (R.next()) {
382	for (int j=0;j<clids.length;j++){
383	indMatrix[i][j]=R.getInt(j+2);
384	}
385	i++;
386	}
387	R.close();
388	S.close();
389	}
390	catch (SQLException e){
391	System.out.println("SQLException: " + e.getMessage());
392	System.out.println("SQLState: " + e.getSQLState());
393	System.out.println("Couldn't get the indices set from columnn "+idxColumn+" in table "+keyTable+" from "+masterDb+" database in "+masterHost+", exiting.");
394	System.exit(2);
395	}
396	return indMatrix;
397	}
398
399
400	}