Actually, salesforce.com has moved

Actually, salesforce.com has moved some kinds of data out of Oracle that previously used to be stored there. Besides Oracle, salesforce uses at least a file system and a RAM-based data store about which I have no details. Even so, much of salesforce.com’s data is stored in Oracle — a single instance of Oracle, which it believes may be the largest instance of Oracle in the world.

Salesforce did spell out some of its database story in a 2008 force.com white paper, which is good stuff, but potentially misleading in one important way. The paper tells of a level of abstraction, whereby what the application sees as logical “columns” are stored in a very different schema than one might assume. However, it doesn’t spell out a second level of abstraction, whereby that logical schema also isn’t how the database is actually laid out.

Another flaw in the paper is that it spins “We had to do this, to support multitenancy, so we did.” issues as “Because we’re multitenant, we can do this, while single-tenant systems can’t.” One example is the query optimization step around “user visibility” in Figure 11. Welcome to marketing.

At the first level of abstraction, data seems to be kept mainly in a single wide table, with hundreds of columns. What’s more, many of those are “flex columns”; a flex column can hold data of many different kinds and even datatypes. Notwithstanding the second level of abstraction, I imagine the idea of stuffing different kinds of thing into the same column has something to do with the fact that Oracle’s physical limit on columns falls far short of the number of logical columns salesforce wants to use.

If we imagine that the different kinds of data in a flex column were each in their own column instead, the whole thing might sound like BigTable/Cassandra/HBase-style column-group NoSQL. Thus, much as Workday uses MySQL to simulate a key-value store, salesforce.com can be said to use Oracle to simulate a different kind of NoSQL. In both cases, what’s going on seems to be a kind of object/relational mapping, but with the relational aspect strongly deemphasized. Or, if you take a more relational view, we could say that salesforce.com’s tables are a lot wider than any one user organization’s, because each user sees only its own custom columns (plus the standard ones common to all users).

The second layer of abstraction has a lot to do with multitenancy. If you want to stick data for many different user organizations into the same huge table, then you have to label it in some way to show who is permitted to see or update each part. Logically, this leads to a join, between one table carrying data plus a simple key showing which users/roles are entitled to see it, and a second table showing who actually is that kind of user/has that kind of role. But that join makes a lot of sense to store in a denormalized way, all the more because data is partitioned across the computer cluster in line with which user organization it actually belongs to.

Multitenant security isn’t the only reason for this denormalization, but it appears to be the biggest one.

The whole thing is doing 550 million or so transactions per day. salesforce.com thinks that fact should be regarded as evidence that it works. :)

Salesforce did spell out some of its database story in a 2008 force.com white paper, which is good stuff, but potentially misleading in one important way. The paper tells of a level of abstraction, whereby what the application sees as logical “columns” are stored in a very different schema than one might assume. However, it doesn’t spell out a second level of abstraction, whereby that logical schema also isn’t how the database is actually laid out.

Another flaw in the paper is that it spins “We had to do this, to support multitenancy, so we did.” issues as “Because we’re multitenant, we can do this, while single-tenant systems can’t.” One example is the query optimization step around “user visibility” in Figure 11. Welcome to marketing.

At the first level of abstraction, data seems to be kept mainly in a single wide table, with hundreds of columns. What’s more, many of those are “flex columns”; a flex column can hold data of many different kinds and even datatypes. Notwithstanding the second level of abstraction, I imagine the idea of stuffing different kinds of thing into the same column has something to do with the fact that Oracle’s physical limit on columns falls far short of the number of logical columns salesforce wants to use.

If we imagine that the different kinds of data in a flex column were each in their own column instead, the whole thing might sound like BigTable/Cassandra/HBase-style column-group NoSQL. Thus, much as Workday uses MySQL to simulate a key-value store, salesforce.com can be said to use Oracle to simulate a different kind of NoSQL. In both cases, what’s going on seems to be a kind of object/relational mapping, but with the relational aspect strongly deemphasized. Or, if you take a more relational view, we could say that salesforce.com’s tables are a lot wider than any one user organization’s, because each user sees only its own custom columns (plus the standard ones common to all users).

The second layer of abstraction has a lot to do with multitenancy. If you want to stick data for many different user organizations into the same huge table, then you have to label it in some way to show who is permitted to see or update each part. Logically, this leads to a join, between one table carrying data plus a simple key showing which users/roles are entitled to see it, and a second table showing who actually is that kind of user/has that kind of role. But that join makes a lot of sense to store in a denormalized way, all the more because data is partitioned across the computer cluster in line with which user organization it actually belongs to.

Multitenant security isn’t the only reason for this denormalization, but it appears to be the biggest one.

The whole thing is doing 550 million or so transactions per day. salesforce.com thinks that fact should be regarded as evidence that it works. :)

0/5000

Dari: -

Ke: -

Hasil (Bahasa Indonesia) 1: [Salinan]

Disalin!

Actually, salesforce.com has moved some kinds of data out of Oracle that previously used to be stored there. Besides Oracle, salesforce uses at least a file system and a RAM-based data store about which I have no details. Even so, much of salesforce.com’s data is stored in Oracle — a single instance of Oracle, which it believes may be the largest instance of Oracle in the world.Salesforce did spell out some of its database story in a 2008 force.com white paper, which is good stuff, but potentially misleading in one important way. The paper tells of a level of abstraction, whereby what the application sees as logical “columns” are stored in a very different schema than one might assume. However, it doesn’t spell out a second level of abstraction, whereby that logical schema also isn’t how the database is actually laid out.Another flaw in the paper is that it spins “We had to do this, to support multitenancy, so we did.” issues as “Because we’re multitenant, we can do this, while single-tenant systems can’t.” One example is the query optimization step around “user visibility” in Figure 11. Welcome to marketing.At the first level of abstraction, data seems to be kept mainly in a single wide table, with hundreds of columns. What’s more, many of those are “flex columns”; a flex column can hold data of many different kinds and even datatypes. Notwithstanding the second level of abstraction, I imagine the idea of stuffing different kinds of thing into the same column has something to do with the fact that Oracle’s physical limit on columns falls far short of the number of logical columns salesforce wants to use.If we imagine that the different kinds of data in a flex column were each in their own column instead, the whole thing might sound like BigTable/Cassandra/HBase-style column-group NoSQL. Thus, much as Workday uses MySQL to simulate a key-value store, salesforce.com can be said to use Oracle to simulate a different kind of NoSQL. In both cases, what’s going on seems to be a kind of object/relational mapping, but with the relational aspect strongly deemphasized. Or, if you take a more relational view, we could say that salesforce.com’s tables are a lot wider than any one user organization’s, because each user sees only its own custom columns (plus the standard ones common to all users).The second layer of abstraction has a lot to do with multitenancy. If you want to stick data for many different user organizations into the same huge table, then you have to label it in some way to show who is permitted to see or update each part. Logically, this leads to a join, between one table carrying data plus a simple key showing which users/roles are entitled to see it, and a second table showing who actually is that kind of user/has that kind of role. But that join makes a lot of sense to store in a denormalized way, all the more because data is partitioned across the computer cluster in line with which user organization it actually belongs to.Multitenant security isn’t the only reason for this denormalization, but it appears to be the biggest one.The whole thing is doing 550 million or so transactions per day. salesforce.com thinks that fact should be regarded as evidence that it works. :)

Sedang diterjemahkan, harap tunggu..

Hasil (Bahasa Indonesia) 2:[Salinan]

Disalin!

Sebenarnya, salesforce.com telah pindah beberapa jenis data dari Oracle yang sebelumnya digunakan untuk disimpan di sana. Selain Oracle, Salesforce menggunakan setidaknya sistem file dan menyimpan data berbasis RAM tentang yang saya tidak detail. Meski begitu, banyak data salesforce.com ini disimpan dalam Oracle -. Satu contoh dari Oracle, yang percaya mungkin contoh terbesar dari Oracle di dunia Salesforce tidak menguraikan beberapa cerita database-nya di 2.008 force.com putih kertas, yang merupakan hal yang baik, tetapi berpotensi menyesatkan dalam satu cara penting. Kertas menceritakan tingkat abstraksi, dimana apa aplikasi dilihatnya sebagai logis "kolom" disimpan dalam sebuah skema yang sangat berbeda dari satu mungkin menganggap. Namun, itu tidak menguraikan tingkat kedua abstraksi, dimana yang skema logis juga tidak bagaimana database sebenarnya ditata. Cacat lain di koran adalah bahwa hal itu berputar "Kami harus melakukan ini, untuk mendukung multitenancy, jadi kami lakukan. "isu-isu sebagai" Karena kita multitenant, kita bisa melakukan ini, sementara sistem single-tenant bisa tidak. "Salah satu contoh adalah langkah optimasi query sekitar" visibilitas pengguna "pada Gambar 11. Selamat Datang pemasaran. Pada tingkat pertama abstraksi, data tampaknya disimpan terutama di meja lebar tunggal, dengan ratusan kolom. Terlebih lagi, banyak dari mereka yang "kolom fleksibel"; kolom fleksibel dapat menyimpan data dari berbagai macam dan bahkan tipe data. Meskipun tingkat kedua abstraksi, aku membayangkan ide isian berbagai hal ke dalam kolom yang sama ada hubungannya dengan fakta bahwa batas fisik Oracle pada kolom jatuh jauh dari jumlah kolom logis Salesforce ingin menggunakan. Jika kita bayangkan bahwa berbagai jenis data dalam kolom fleksibel masing-masing dalam kolom mereka sendiri bukan, semuanya mungkin terdengar seperti Bigtable / Cassandra / HBase gaya kolom-kelompok NoSQL. Dengan demikian, sebanyak hari kerja menggunakan MySQL untuk mensimulasikan penyimpanan kunci-nilai, salesforce.com dapat dikatakan menggunakan Oracle untuk mensimulasikan berbagai jenis NoSQL. Dalam kedua kasus, apa yang terjadi tampaknya menjadi semacam objek / pemetaan relasional, tetapi dengan aspek hubungan kuat perlombaan. Atau, jika Anda mengambil pandangan yang lebih relasional, kita bisa mengatakan bahwa tabel salesforce.com ini jauh lebih luas daripada satu organisasi pengguna, karena setiap pengguna hanya melihat kolom sendiri kustom (plus yang standar umum untuk semua pengguna). Yang kedua lapisan abstraksi memiliki banyak hubungannya dengan multitenancy. Jika Anda ingin tetap data untuk banyak organisasi pengguna yang berbeda ke dalam meja besar yang sama, maka Anda harus label itu dalam beberapa cara untuk menunjukkan siapa yang diizinkan untuk melihat atau memperbarui setiap bagian. Logikanya, ini mengarah ke bergabung, antara satu meja membawa data ditambah menunjukkan kunci sederhana yang pengguna / peran berhak untuk melihatnya, dan meja menunjukkan kedua yang benar-benar adalah bahwa jenis user / memiliki jenis peran. Tapi itu bergabung membuat banyak akal untuk menyimpan dengan cara denormalized, semua lebih karena data dipartisi di cluster komputer sejalan dengan mana organisasi pengguna itu benar-benar milik. Keamanan multitenant bukan satu-satunya alasan untuk denormalization ini, tapi tampaknya menjadi yang terbesar. Semuanya melakukan 550 juta atau lebih transaksi per hari. salesforce.com berpikir bahwa sebenarnya harus dianggap sebagai bukti bahwa ia bekerja. :)

Sedang diterjemahkan, harap tunggu..

Hasil (Bahasa Indonesia) 3:[Salinan]

Disalin!

Sedang diterjemahkan, harap tunggu..

Bahasa lainnya

Dukungan alat penerjemahan: Afrikans, Albania, Amhara, Arab, Armenia, Azerbaijan, Bahasa Indonesia, Basque, Belanda, Belarussia, Bengali, Bosnia, Bulgaria, Burma, Cebuano, Ceko, Chichewa, China, Cina Tradisional, Denmark, Deteksi bahasa, Esperanto, Estonia, Farsi, Finlandia, Frisia, Gaelig, Gaelik Skotlandia, Galisia, Georgia, Gujarati, Hausa, Hawaii, Hindi, Hmong, Ibrani, Igbo, Inggris, Islan, Italia, Jawa, Jepang, Jerman, Kannada, Katala, Kazak, Khmer, Kinyarwanda, Kirghiz, Klingon, Korea, Korsika, Kreol Haiti, Kroat, Kurdi, Laos, Latin, Latvia, Lituania, Luksemburg, Magyar, Makedonia, Malagasi, Malayalam, Malta, Maori, Marathi, Melayu, Mongol, Nepal, Norsk, Odia (Oriya), Pashto, Polandia, Portugis, Prancis, Punjabi, Rumania, Rusia, Samoa, Serb, Sesotho, Shona, Sindhi, Sinhala, Slovakia, Slovenia, Somali, Spanyol, Sunda, Swahili, Swensk, Tagalog, Tajik, Tamil, Tatar, Telugu, Thai, Turki, Turkmen, Ukraina, Urdu, Uyghur, Uzbek, Vietnam, Wales, Xhosa, Yiddi, Yoruba, Yunani, Zulu, Bahasa terjemahan.