Daily Report

Task Summary

  • Data analysis on my study.
  • Routine task
    • Learning English


  • Check the deviances are normally distributed
    • Visualize distribution.
  • [doing] Summarize the results of subject selection.
    • Generated chart of point plot.
  • [pending] Create a web app for online experiment.


  • SQL Antipatterns
    • Why time complexity of join is exponential?
      • On MySQL5.6
        • Nested Loop Join algorithm is used for non-indexed columns.
          • Why NLB is used for non-indexed columns?
            • Unnecessary
        • Block Nested Loop Join algorithm is used for indexed columns.
          • falster
          • Join Buffer Size
            • default 256 kilo bytes
            • max 4GB -1
          • By using buffer, it reduce the calculation cost
    • Polymorphic Associations (Promiscuous Association)
      • Polymorphic Associations
      • CREATE TABLE Comments (
          comment_id    SERIAL PRIMARY KEY,
          issue_type    VARCHAR(20), -- 'Bugs' or 'FeatureRequests',
          issue_id      BIGINT UNSIGNED NOT NULL,
          author        BIGINT UNSIGNED NOT NULL,
          comment_date  DATETIME,
          comment       TEXT,
          FOREIGN KEY (author) REFERENCES Accounts(account_id)
      • It may cause metadata contamination.
      • Solution
        • Reversing dependency.
        • Use cross tables.
        • Cross Reference Tables
        • It does not prevent duplication of multiple associations, which needs to be handled by the application code.
        • COALESCE (SQL-92 compatible)

Coding Test

  • Skip

What to do tomorrow

  • Decide on the content of my paper.
    • Think about the general structure of your paper.
    • Think about the questions and organize the content.
    • Read Makishita’s paper and check the chapter headings.
    • Read Makishita’s paper and check the introduction and experimental methods.
    • Read Kotake’s paper and check the pre-experimental methods.
    • Read Shimokawara’s paper and check the experimental methods.
    • Research MAMA by reading articles on previous studies.
  • Analyze and summarize the data.
    • Subject selection
      • FBCR
      • distributions
    • Adaptive Method
      • About number of trials and entropy
      • Credible interval and confidence interval
      • Efficiency
    • Constant method
      • Deviance
      • Adaptation
      • Confidence interval
      • Left-right difference



  • Wrote down the tasks in detail.

Problem and Try

Free Space

Takizawa Tetsu
Takizawa Tetsu