Nonreplicated Static Data Allocation in Distributed Databases Using Biogeography-Based Optimization

Algorithm 1

Step 1: Initialize Population Size, Maximum Number of Iterations (NI), Maximum Immigration rate (I), Maximum Emigration

   rate (E), Mutation rate, and Elitism Parameter;

Step 2: Generate a random set of habitats based on the size of the population. Each habitat corresponds to a potential solution

   to the given problem;

Step 3: Evaluate habitats and compute corresponding HSI value of each habitat;

Step 4: For 𝑖=1 to NI

Step 5: Calculate the immigration rate (λ) and emigration rate (μ) for each habitat according to HSI of each habitat;

      /* Start of Migration */

Step 6: Select non-elite habitat 𝐻_𝑖 with probability ∝ 𝜆_𝑖 for immigration;

Step 7: if 𝐻_𝑖 is selected then select 𝐻_𝑗 with probability ∝ 𝜇_𝑗 for emigration;

Step 8: if 𝐻_𝑗 is selected then randomly select a SIV from 𝐻_𝑗;

Step 9: 𝐻_𝑖 (SIV)← 𝐻_𝑗 (SIV);

Step 10: End if

Step 11: End if

      /* End of Migration */

      /* Start of Mutation */

Step 12: Select an SIV in 𝐻_𝑖 with probability based on the mutation rate;

Step 13: if 𝐻_𝑖 (SIV) is selected then replace 𝐻_𝑖 (SIV) with a randomly generated SIV;

Step 14: End if

      /* End of Mutation */

Step 15: Re-evaluate habitats and compute corresponding HSI value of each habitat;

Step 16: End for