Njengonjiniyela, ngivame ukuzithola ngisebenza ngemininingwane egciniwe ehlukene, edinga ulwazi lwe-SQL (Ulimi Oluhlelekile Lwemibuzo). Lolu limi olunamandla lokuhlela lunikeza izindlela zokufinyelela, zokuphatha, kanye nokukhohlisa idatha egcinwe kuzingosi zolwazi ezihlobene. Isimo esisodwa esivamile esingase senzeke phakathi nale misebenzi isidingo sokukhomba ukuxhumana kwamanje kusizindalwazi. Kungaba nezizathu ezahlukahlukene zale mfuneko, njengokulungisa ukusebenza kwesizindalwazi, ukuhlonza ukuxhumana okungenzi lutho noma izimo zokusetshenziswa ngokweqile, phakathi kokunye.
Ukuqonda ukuxhumana kwesizindalwazi kubalulekile ekuhleleni nasekuphatheni isizindalwazi okusebenzayo kwe-SQL. I-SQL isinikeza ikhambi lokuqapha lokhu kuxhumana sisebenzisa imisebenzi nemibuzo eyakhelwe ngaphakathi. Akuyona umsebenzi oyinkimbinkimbi, kodwa odinga ukuqonda nokunemba okuthile. Ezigabeni ezilandelayo, sizogxila kakhulu endleleni yokubonisa ukuxhumana kwamanje kusizindalwazi sisebenzisa i-SQL futhi sichaze isinyathelo ngasinye sekhodi esetshenziswayo.
Ihlola Pg_stat_activity View
I-PostgreSQL inikeza umbono wekhathalogi yesistimu owaziwa ngokuthi i-pg_stat_activity ongasetshenziswa abaphathi bedatha ukuthola imininingwane mayelana nokuxhumana kwamanje/izinqubo ezisebenzayo kudathabheyisi. Lo mbono ubonisa umugqa owodwa ngenqubo yeseva, ubonisa ulwazi oluhlobene nomsebenzi wamanje waleyo nqubo.
SELECT * FROM pg_stat_activity;
Lapho usebenzisa lo mbuzo ongenhla, uzobuyisa idatha efana negama lohlelo lokusebenza elixhunyiwe, igama lesizindalwazi, ikheli leklayenti, umbuzo wamanje oqhutshwayo, nokunye.
Ukuqonda Ikhodi Yombuzo
- The KHETHA * umyalo usetshenziselwa ukukhetha wonke amakholomu kuthebula/ukubuka.
- The KUPHELA Igama elingukhiye libonisa ithebula noma buka lapho idatha ilandwa khona. Kulokhu, kunjalo pg_stat_activity, ukubuka kwekhathalogi ephethe ulwazi mayelana nezinqubo zeseva noma ukuxhumana.
Ukuhlunga Izixhumanisi Ezingasebenzi
Ngokuvamile, ungase ungabi nesifiso sokwazi zonke izixhumanisi kodwa kuphela lezo ezingasebenzi. Ungahlunga izixhumanisi ezinjalo usebenzisa inkambu yesimo ekubukeni kwe -pg_stat_activity.
SELECT * FROM pg_stat_activity WHERE state = 'idle';
Le khodi izobuyisela kuphela lokho kuxhumana lapho isimo 'singenzi lutho', okungukuthi, ukuxhumana okungasetshenziselwa noma yimiphi imisebenzi esebenzayo okwamanje.
Iqhaza Leminye Imisebenzi Ye-SQL Nemitapo Yolwazi
Ngaphezu kwe-SQL eyinhloko kanye nemisebenzi yayo, kunemitapo yolwazi eminingi ye-SQL kanye nemisebenzi ethuthukisa kakhulu amakhono e-SQL lapho isebenza ngama-database. Izibonelo zifaka phakathi, kodwa kungagcini lapho, i-SQLAlchemy ye-Python, i-JDBC kanye ne-JPA ye-Java, enikeza ukucashunwa ngaphezu kwe-SQL ukuze kube nokuhlela okukhululekile nokuphumelelayo.
Khumbula, ukuphatha kahle ukuxhumana kwedathabheyisi kuyisici esibalulekile sokuphatha idathabheyisi yakho, ukuthuthukisa ukusebenza kwayo, nokuyigcina iphephile. Ngakho-ke lolu lwazi lwakha itshe lesisekelo lohlelo lwe-SQL olusezingeni eliphezulu kanye nokuphathwa kwedathabheyisi okuphumelelayo.
