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InstantDB: Very slow 4-way join


I have a 4 tables, the first with a one-element key and each of the 
others having the key of the table before plus one element.

That is
table t1: primary key k1
table t2: primary key k1, k2
table t3: primary key k1, k2, k3
table t4: primary key k1, k2, k3, k4

I want to join  those four tables and get all the records for a 
particular k1 value.

Since InstantDB doesn't support indexed range matches (or partial key 
matches), I added an index to t2, t3, & t4 on the values to match from 
the higher table.

That is
table t2: non-unique index on k1
table t3: non-unique index on k1, k2
table t4: non-unique index on k1, k2, k3

Then I do a join with the following where clause:
  where t1.k1 = <some key value>
   and t2.k1 = t1.k1
   and t3.k1 = t2.k1
   and t3.k2 = t2.k2
   and t4.k1 = t3.k1
   and t4.k2 = t3.k2
   and t4.k3 = t3.k3

It took 11.109 seconds to insert 50 t1 records + associated t2, t3, & t4 
records.
It then took 162.328 seconds to select the 96 records associated with 
one k1 value.

By contrast, the same query against a similar but commercial pure-Java 
database took 0.335 seconds.
(It did take that database 18.382 seconds for the inserts, although when 
you go to 150 t1 records the lead drops idb=48sec, pb=53sec).

The same query in InstantDB with 150 t1 reords took over 32 minutes.

I've attached a short Java program that creates the tables, inserts the 
records, and does the select (it should only need a test.prp file in the 
same dir). Please let me know if this is due to a flaw in my code or if 
it's just a limitation of InstantDB.

Thanks,

Scott Plante

import java.sql.*;
import java.util.*;

public class X
{
  private static Driver d = new org.enhydra.instantdb.jdbc.idbDriver();

  public static int MAX_CONF = 50;
  public static int MAX_PART = 6;

  public static void main(String args[])
      throws Exception
  {
    long startTime = 0;
    long insertTime = 0;
    long endTime = 0;
    
    Connection con = null;
    Statement stmt = null;
    PreparedStatement ps = null;
    ResultSet rs = null;
    try
    {
      con = DriverManager.getConnection("jdbc:idb=test.prp","","");
      stmt = con.createStatement();

      startTime = System.currentTimeMillis();

      stmt.execute("DROP TABLE t1");
      stmt.execute("DROP TABLE t1");
      stmt.execute("DROP TABLE t2");
      stmt.execute("DROP TABLE t3");
      stmt.execute("DROP TABLE t4");
      stmt.execute("CREATE TABLE t1 ("
          + " k1 long,"
          + " data1 char(128) )"
          + " UNIQUE (k1)"
          + " PRIMARY KEY (k1)");

    
      stmt.execute("CREATE TABLE t2 ("
          + " k1 long,"
          + " k2 char(10),"
          + " data2 char(128) )"
          + " UNIQUE (k1,k2)"
          + " PRIMARY KEY (k1,k2)");

      stmt.execute(" CREATE TABLE t3 ("
          + " k1 long,"
          + " k2 char(10),"
          + " k3 char(10),"
          + " data3 char(128) )"
          + " UNIQUE (k1,k2,k3)"
          + " PRIMARY KEY (k1,k2,k3)");

      stmt.execute(" CREATE TABLE t4 ("
          + " k1 long,"
          + " k2 char(10),"
          + " k3 char(10),"
          + " k4 char(10),"
          + " data4 char(128) )");

      stmt.execute(" CREATE INDEX t2idx1 on t2"
          + " (k1)");
      stmt.execute(" CREATE INDEX t3idx1 on t3"
          + " (k1,k2)");
      stmt.execute(" CREATE INDEX t4idx1 on t4"
          + " (k1,k2,k3)");


      ps = con.prepareStatement("insert into t1 values ( ?, ? )");
      for (int i=0;i<MAX_CONF;i++)
      {
        if (i%10==0)
          System.out.println("t1: i="+i);
        ps.setLong(1,i);
        ps.setString(2,"CONFERENCE NUMBER " + i 
            + "  Abcdefghijk lmno pqrst uvwxyz 12 345 678 90");
        ps.execute();
      }

      ps = con.prepareStatement("insert into t2 values ( ?, ?, ? )");
      for (int i=0;i<MAX_CONF;i++)
      {
        if (i%10==0)
          System.out.println("t2: i="+i);
        for (int j=0;j<MAX_PART;j++)
        {
          ps.setLong(1,i);
          ps.setString(2,"J"+j);
          ps.setString(3,"CONFERENCE NUMBER " + i 
              + " PARTICIPANT NUMBER " + j
              + "  Abcdefghijk lmno pqrst uvwxyz 12 345 678 90");
          ps.execute();
        }
      }

      ps = con.prepareStatement("insert into t3 values ( ?, ?, ?, ? )");
      for (int i=0;i<MAX_CONF;i++)
      {
        if (i%10==0)
          System.out.println("t3: i="+i);
        for (int j=0;j<MAX_PART;j++)
        {
          for (int k=0;k<cts(k);k++)
          {
            ps.setLong(1,i);
            ps.setString(2,"J"+j);
            ps.setString(3,"K"+k);
            ps.setString(4,"CONFERENCE NUMBER " + i 
                + " PARTICIPANT NUMBER " + j
                + " CT NUMBER " + k
                + "  Abcdefghijk lmno pqrst uvwxyz 12 345 678 90");
            ps.execute();
          }
        }
      }

      ps = con.prepareStatement("insert into t4 values ( ?, ?, ?, ?, ? )");
      for (int i=0;i<MAX_CONF;i++)
      {
        if (i%10==0)
          System.out.println("t4: i="+i);
        for (int j=0;j<MAX_PART;j++)
        {
          for (int k=0;k<cts(k);k++)
          {
            for (int l=0;l<cts(l);l++)
            {
              ps.setLong(1,i);
              ps.setString(2,"J"+j);
              ps.setString(3,"K"+k);
              ps.setString(4,"L"+l);
              ps.setString(5,"CONFERENCE NUMBER " + i 
                  + " PARTICIPANT NUMBER " + j
                  + " CT NUMBER " + k
                  + " CON NUMBER " + l
                  + "  Abcdefghijk lmno pqrst uvwxyz 12 345 678 90");
              ps.execute();
            }
          }
        }
      }

      insertTime = System.currentTimeMillis();
      System.out.println("Insert done, ms="
          + (insertTime - startTime));

      rs = stmt.executeQuery("select "
          + " t1.k1,"
          + " t2.k2,"
          + " t3.k3,"
          + " t4.k4,"
          + " data1,"
          + " data2,"
          + " data3,"
          + " data4"
        + " from t1, t2, t3, t4"
        + " where t1.k1 = " + (MAX_CONF / 2)
          + " and t2.k1 = t1.k1"
          + " and t3.k1 = t2.k1"
          + " and t3.k2 = t2.k2"
          + " and t4.k1 = t3.k1"
          + " and t4.k2 = t3.k2"
          + " and t4.k3 = t3.k3"
        + " order by t1.k1, t2.k2, t3.k3, t4.k4");

      int recCtr = 0;
      while (rs.next())
      {
        recCtr++;
        System.out.println(
            "CONF " + rs.getLong(1)
            + " PT " + rs.getString(2)
            + " CT " + rs.getString(3)
            + " Cn " + rs.getString(4)
            + " d4 " + rs.getString(8));
      }

      endTime = System.currentTimeMillis();
      System.out.println("Insert time, ms="
          + (insertTime - startTime));
      System.out.println("Select time, ms="
          + (endTime - insertTime)
          + ", record count="
          + recCtr);
    }
    finally
    {
      try
      { if (rs!=null) rs.close(); }
      catch (SQLException ex)
      { ex.printStackTrace(); } 

      try
      { if (ps!=null) ps.close(); }
      catch (SQLException ex)
      { ex.printStackTrace(); } 

      try
      { if (stmt!=null) stmt.close(); }
      catch (SQLException ex)
      { ex.printStackTrace(); } 

      try
      { if (con!=null) con.close(); }
      catch (SQLException ex)
      { throw ex; } 
    }
  }

  public static int cts(int i)
  {
    int j = (i % 10);
    if (j > 3)
      return 1;
    return j + 2;
  }
  public static int cons(int i)
  {
    int j = (i % 10);
    if (j > 2)
      return 1;
    return j + 2;
  }
}