MySQL Partition ( VER 5.6.6 up)

1. Origin Table

CREATE TABLE `TEST` (
  `NO` int(11) NOT NULL AUTO_INCREMENT,
  `TIME` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `ID` varchar(32) NOT NULL,
  `EVENTNO` int(11) NOT NULL DEFAULT '0',
  `VALUENO` int(11) NOT NULL DEFAULT '0',
  `VALUE` bigint(11) NOT NULL DEFAULT '0',
  PRIMARY KEY (`NO`),
  KEY `ID` (`ID`),
  KEY `EVENTNO` (`EVENTNO`),
  KEY `VALUENO` (`VALUENO`)
) ENGINE=MyISAM AUTO_INCREMENT=0

 ALTER TABLE TEST DROP PRIMARY KEY, ADD UNIQUE KEY `ID_EVENTNO_VALUENO` (`ID`,`EVENTNO`,`VALUENO`), ADD UNIQUE KEY `NO_EVENTNO` (`NO`,`EVENTNO`), DROP KEY `VALUENO`;
ALTER TABLE TEST PARTITION BY HASH(`EVENTNO`) PARTITIONS 10;


PS : We could  also DROP KEY `ID` and `EVENTNO` ...

Use EVENTNO to be Hash Key into 10 partition


2. Explain

EXPLAIN PARTITIONS SELECT VALUE FROM TEST WHERE ID = 'AAAA' AND EVENTNO = 200015 AND VALUENO = 10008;

+----+-------------+-----------------+------------+-------+-------------------------------+--------------------+---------+-------------------+------+-------+
| id | select_type | table           | partitions | type  | possible_keys                 | key                | key_len | ref               | rows | Extra |
+----+-------------+-----------------+------------+-------+-------------------------------+--------------------+---------+-------------------+------+-------+
|  1 | SIMPLE      | TEST | p5         | const | ID_EVENTNO_VALUENO,ID,EVENTNO | ID_EVENTNO_VALUENO | 74      | const,const,const |    1 | NULL  |
+----+-------------+-----------------+------------+-------+-------------------------------+--------------------+---------+-------------------+------+-------+

partitions = p5      ==> we use EVENTNO to partition
key  ID_EVENTNO_VALUENO  
rows = 1 , only 1 row, good index



3. Partition Rule

A: HASH (N) ,  N must be an integer

B:  All columns used in the partitioning expression for a partitioned table must be part of every unique key that the table may have.
(https://dev.mysql.com/doc/refman/5.6/en/partitioning-limitations-partitioning-keys-unique-keys.html)

也就是說 拿來當 Partition 的Key, 必須存在在所有的 Primay / Unique Key中

GenyMotion Google Play and ARM(CPU_ABI_INCOMPATIBLE) Support

1.  Google Play

https://gist.github.com/wbroek/9321145

Google Apps for Android 5.0 (https://www.androidfilehost.com/?fid=95784891001614559 - gapps-lp-20141109-signed.zip)

Google Apps for Android 4.4.4 (https://www.androidfilehost.com/?fid=23501681358544845 - gapps-kk-20140606-signed.zip)

Google Apps for Android 4.3 (https://www.androidfilehost.com/?fid=23060877490000124 - gapps-jb-20130813-signed.zip)

Google Apps for Android 4.2 (https://www.androidfilehost.com/?fid=23060877490000128 - gapps-jb-20130812-signed.zip)

Google Apps for Android 4.1 (https://www.androidfilehost.com/?fid=22979706399755082 - gapps-jb-20121011-signed.zip)

Google Apps for Android 2.3.7 (http://www.mediafire.com/download/bs063kb0m742o5l/gapps-gb-20131027-signed.zip - gapps-gb-20131027-signe.zip)

2. Install ARM

http://filetrip.net/dl?4SUOrdcMRv

Other Ref:

http://forum.xda-developers.com/showthread.php?t=2528952

Get Other App Status in Android

1. Before API Level 21 (Lolipop , 5.0 )

ref:
http://stackoverflow.com/questions/22500959/detect-when-other-application-opened-or-launched

http://developer.android.com/reference/android/app/ActivityManager.html

getRunningAppProcesses()

Returns a list of application processes that are running on the device.

getRunningTasks(int maxNum)

This method was deprecated in API level 21. As of LOLLIPOP, this method is no longer available to third party applications: the introduction of document-centric recents means it can leak person information to the caller. For backwards compatibility, it will still retu rn a small subset of its data: at least the caller's own tasks, and possibly some other tasks such as home that are known to not be sensitive.

A : Get Running Processes Lists

ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningAppProcessInfo> runningAppProcessInfo = am.getRunningAppProcesses();

for (int i = 0; i < runningAppProcessInfo.size(); i++) {
  if(runningAppProcessInfo.get(i).processName.equals("com.the.app.you.are.looking.for") {
    // Do you stuff
  }
}

B: Get Top Task ( Foreground Tasks)

public static boolean isForeground(Context ctx, String myPackage){
    ActivityManager manager = (ActivityManager) ctx.getSystemService(ACTIVITY_SERVICE);
    List< ActivityManager.RunningTaskInfo > runningTaskInfo = manager.getRunningTasks(1); 

    ComponentName componentInfo = runningTaskInfo.get(0).topActivity;
    if(componentInfo.getPackageName().equals(myPackage)) {
        return true;
    }       
    return false;
}

2. After API Level 21 (Lolipop)

the getRunningTasks is deprecated


other approach :
getAppTasks 
http://developer.android.com/reference/android/app/ActivityManager.html#getAppTasks%28%29


http://www.intertech.com/Blog/android-5-api-changes-getapptasks/

WebView Size Problem in Andorid 4.4

1. the webpage will over screen size

ref :
https://developer.android.com/guide/webapps/migrating.html


add :

WebSettings settings = webView.getSettings();
settings.setUseWideViewPort(true);
settings.setLoadWithOverviewMode(true);

Other:
set webview background color

myWebView.setBackgroundResource(Color.TRANSPARENT);
myWebView.setBackgroundColor(Color.TRANSPARENT);

Disable TitleBar(ActionBar) in Android App

1. Activity shouldn't exntend ActionBarActivity

public class MainActivity extends ActionBarActivity {

public class MainActivity extends Activity {


2. in AndroidManifest.xml

            android:name=".MainActivity"
            android:label="@string/app_name"
            android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >

Android WebView App Crash on Android 4.4 in GenyMotion

In LogCat

Some errors like

eglCodecCommon﹕ **** ERROR unknown type  (many)
GL ERROR :GL_INVALID_ENUM : glProduceTextureCHROMIUM: target was GL_TEXTURE_EXTERNAL_OES


temporary disable hardware accelerate

in AndroidManifest.xml

.
.
android:hardwareAccelerated="false"
.
.>


reference :
http://stackoverflow.com/questions/26836858/android-genymotion-vm-logcat-runs-into-infinite-loop



http://blog.csdn.net/lfdfhl/article/details/9139259

CentOS SELinux http bind port (http listen port other than (80, 81, 443, 488, 8008, 8009, 8443, 9000)

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Managing_Confined_Services/chap-Managing_Confined_Services-The_Apache_HTTP_Server.html



1. List current allowed port

semanage port -l | grep -w http_port_t

http_port_t                    tcp      80, 81, 443, 488, 8008, 8009, 8443, 9000


2. Add another port

semanage port -a -t http_port_t -p tcp 12345